Why Do My Display Settings Keep Changing On My Mac?

Macs are among the most popular and easy-to-recognize computers in today’s market. This popularity and widespread use are mainly because of their high-quality build and productivity-focused design. However, like many other computers, Macs can also have hardware and software issues, even affecting the computer’s display settings.

These problems could result in modifications to your screen resolution or refresh rate, but it’s not uncommon to notice changes to screen arrangement settings, especially if you’re using multiple displays.

Why Do The Display Settings Keep Changing?

Regardless of what kind of Mac you own, your display settings aren’t usually supposed to change unless you modify them.

While these unauthorized changes might not always be problematic, they can be symptoms of a more severe problem with your computer.

However, you might also notice more serious changes to your Mac’s display, especially with window sizes and screen resolutions.

These changes can affect your productivity or even hamper the performance of some programs on your computer.

Therefore, it’s necessary to determine the problem and how to fix it.

Here are a few reasons your Mac display settings keep changing:

  • Buggy or outdated operating system.
  • Corrupt preferences files.
  • Display driver issues.
  • Virus or malware.
  • Your Mac is set to rearrange spaces automatically.
  • Hardware problems.

The next section of this article explains each of the abovementioned causes and includes a step-by-step guide to resolving them.

An iMac with with the desktop environment.

1. Buggy or Outdated Operating System

It’s no newsflash that an outdated or buggy operating system could cause some problems for your Mac. After all, a computer’s operating system or OS is its core software program.

This program controls every other program on the computer, as well as processes and critical functions.

Therefore, bugs in an OS can lead to minor problems in a Mac’s functionality and significant issues with its performance and features.

It can be challenging to track exactly how the operating system affects your computer or computer settings, especially if you’re not technically minded. Still, you can look out for some telltale signs.

An excellent way to know if the problem with your display settings stems from an outdated or buggy operating system is if the problem pops up after you perform a software update on your Mac.

However, the problem can still stem from your Mac’s OS, even if you haven’t updated your computer in a while. In this case, the problem might be because your operating system is outdated.

How To Fix

It’s pretty easy to fix your Mac display settings if the problem is with the operating system. All you need to do is to perform a software update on your computer.

This process will require an internet connection and can be done in a few minutes.

Here’s how to perform a software update on your Mac:

  1. Open the Apple Menu on your Mac.
  2. Select “System Preferences” from the menu list.
  3. Click on the “Software Update” button.
  4. Choose “Check For Updates.”

You can also try restarting your Mac if you suspect the problem is with the operating system. This process might not always clear the issues with your display settings, but it’s worth a try.

In fact, restarting your computer should be your first step if you notice the display settings keep changing.

2. Corrupt Preferences Files

While your Mac’s operating system is the “god in the machine” that controls all the computer’s operations, preferences files are application-specific. These programs are system files and are part of every application and function on your Mac.

They instruct application programs on how to behave and include parameters for the functioning of these programs.

Preferences files are essential to every application and process on your computer, including your Mac’s display settings.

Therefore, a problem with the display settings preference files might lead to glitches and memory problems. These could result in your Mac being unable to save modifications to its display settings or lead to settings resets.

These resets typically happen after your computer sleeps, but you might also notice them randomly.

Your computer’s preferences file might become corrupt if the Mac shuts down unexpectedly, after an application crash, or if your hard disk is damaged.

It might also be due to malware or buggy antivirus software.

How To Fix

You can fix corrupt preferences files on your Mac by performing a software update, but this might not always be enough. Therefore, I recommend updating your computer and then resetting its PRAM.

The PRAM (or Parameter Random Access Memory) is a type of memory that keeps its data even after you turn off your Mac.

This Mac-specific memory is similar to NVRAM (Non-Volatile Random Access Memory) and stores simple settings related to time, date, display, and other parameters.

Here’s how to reset your Mac’s PRAM:

  1. Turn off your Mac.
  2. Locate and hold down the “Command,” “Option,” “P,” and “R” keys.
  3. Click the power button to turn on your Mac without letting go of the other keys.
  4. Keep holding the keys until you hear the startup sound twice.
  5. Let go of the keys.

Your Mac will restart with its PRAM reset if you follow the instructions above carefully. You can tell if your PRAM is reset if your computer’s date and time, display, and volume settings are set to default.

All modified display settings on your Mac should now stick and not change unless you manually change them.

Resetting a Mac’s PRAM won’t lead to data loss, so you can do it without worrying about losing any valuable work.

3. Display Driver Issues

Your Mac’s display drivers might also be why its display settings keep changing. Display drivers are programs that facilitate communication between the operating system and the connected display devices.

They manage everything from refresh rate to resolution and parameters like color depth and window size.

Display drivers are very similar to preferences files but handle an entirely different aspect of an application’s processes.

However, you can tell if they’re to blame if the problem only affects one application or pops up when you use a particular application.

Another way to tell if the driver is the culprit is if you notice the display settings changing when you connect your Mac to an external monitor.

The most commonly affected setting is your screen’s resolution, but you might also notice issues with their refresh rates. 

How To Fix

You can fix display driver issues by restarting your Mac or performing a software update on your computer. Another excellent way to resolve the problem is by rebooting it in Safe Mode.

Safe Mode is a computer system starting diagnostic mode that enables users to address issues with the operating system.

However, it can also help detect and clear problems with core system functions and files.

Here’s how to reboot your Mac in safe mode:

  1. Turn off your Mac.
  2. Hold the power button on your computer for a few seconds until the “Loading Startup Options” screen appears.
  3. Pick a storage volume.
  4. Long press the shift key and select “Continue In Safe Mode.”

It’s that easy!

4. Virus or Malware

Viruses are nasty for many reasons. But they can affect your Mac’s processes and process files by infecting programs, posing as a program, or removing essential files and software programs.

They typically result in several problems, including glitches in settings.

Your Mac display settings might change because of one or more viruses on your computer.

These harmful programs typically get into your system if you download unverified files from sketchy sites or through external drives.

How To Fix

Regardless of how the virus or malware might have infected your system, you can get rid of it by downloading and installing an antivirus program.

Antiviruses typically quarantine and remove infected files and programs.

Here’s how to install and run an antivirus on your Mac:

  1. Download an antivirus software program from the internet.
  2. Open the installer file when the download is finished, then follow the on-screen instructions to install the program.
  3. Open the antivirus program when the installation is finished and do a comprehensive system scan to look for viruses affecting your Mac.
  4. Set up the antivirus software to do routine scans and updates.

Unfortunately, running an antivirus on your Mac might result in some data loss. But it’s a necessary evil.

Always verify your Mac’s system requirements before downloading and installing antivirus software to ensure you use the right software for your computer. 

5. Your Mac Is Set To Rearrange Spaces Automatically

Mac Spaces, or Spaces, is a Mission Control feature that allows users to open alternative virtual screens on a single device.

Users can run multiple “screens” without installing additional software, connecting external devices, or changing any existing display settings.

However, this feature can also be why your Mac’s display settings keep changing.

Spaces can cause your screens to switch all by themselves, but it can also affect your display settings—particularly window size.

How To Fix

Fortunately, it’s pretty easy to disable the feature that causes spaces to rearrange automatically on your Mac.

It’s known as Automatic Space Switching or Auto Switching, and you can turn it off in Mission Control settings.

Here’s how to disable Automatic Space Switching on your Mac by adjusting your device settings:

  1. On your Mac, select the Apple menu.
  2. Click on “System Preferences” from the list on the screen.
  3. Choose “Mission Control” from the menu.
  4. Choose “Displays have separate spaces” on the screen.
  5. Restart your Mac.

You can also disable Automatic Space Switching by writing a simple script on Terminal. I recommend using this method if the problem doesn’t disappear after adjusting your device settings.

Here’s how to disable Automatic Space Switching on your Mac by writing a simple script on Terminal:

  1. Open Terminal by looking in the Finder’s “Applications” folder or using Spotlight to find the program.
  2. Type the command “defaults write com.apple.dock workspaces-auto-swoosh -bool NO killall Dock” in the Terminal Window.
  3. Restart your Mac.

Ensure you type only the correct commands when working on your Terminal.

6. Hardware Problems

Ultimately, your Mac’s display settings might also result from hardware problems.

These problems are pretty extensive, and they can be anything from issues with your computer’s motherboard to charging and power-related problems.

It’s not always to tell if the problem is with your Mac’s hardware, but some telltale signs can help point you in the right direction. One of these is physical signs of deterioration.

Your computer’s hardware is most likely the culprit if it’s damaged, broken, or unsuitable. This hardware might not directly interface with your Mac’s display but can affect it.

Watch out for damaged HDMI cables and connection ports if you experience a problem using external monitors. These might seem small, but they’re just as important.

How To Fix

The best way to fix hardware problems is by reaching out to a professional. However, you can also try solutions like resetting your Mac’s PRAM or updating display drivers.

These might work temporarily, but you might notice the problem returning when your computer wakes up.

In this case, you’ll need to disable display sleep on your Mac.

Here’s how you can turn off display sleep on a Mac:

  1. Select the Apple Menu on your Mac.
  2. Click the “System Preferences” option.
  3. Choose “Energy Saver.”
  4. Unselect “Put the display to sleep when the computer is inactive.”

You can also use Terminal if this option doesn’t work.

Here’s how to prevent your Mac’s display from sleeping using Terminal:

  1. Open Terminal.
  2. Type “caffeinate” and press Enter.

This method will keep your Mac from sleeping until you close the Terminal window.

Disabling sleep on your computer will drastically affect your Mac’s battery life if you’re not plugged into an outlet.