Selected items unselect every few seconds in macOS 27.2

Once you select an item (file/folder/etc.) in Finder, that item should remain selected until you take action. The issue you report has been seen by others, and is typically caused by a specific background app or process repeatedly stealing window focus or resetting the Finder interface, which makes it feel like your selections are "blinking" away. The typical culprits are Google Chrome and system-level 'helpers/protectors'.

To fix the rapid app and file deselection bug on macOS 27.2, try these steps to isolate and eliminate the conflict:

Identify Background Apps (Most Common Cause)

Background utilities that actively monitor or modify your interface frequently cause this loop. 

• Third-Party Utilities: Completely close or temporarily uninstall any third-party window managers, mouse customization software, clipboard history keepers, VPNs, or aggressive anti-virus/cleaner apps.
• Google Chrome: Google Chrome or its associated update helpers can sometimes trigger rapid background deselect behavior; try completely quitting Chrome to see if the blinking stops.

If those prove effective, then be aware that 3rd party ‘protection’ software is often problematic, and includes:

• Cleaners (software claiming to automatically free up space)
• Optimizers (software claiming to make your Mac run faster)
• Antivirus software
• VPN software (unless provided by a school/employer to enable access to internal resources from a remote location)

Such 3rd party system ‘helpers’, ‘cleaners’ and ‘protectors’ do more harm than good. In fact, such products are completely unnecessary for macOS and the only ‘good’ (if you want to call it that) they do is to put money in the developers’ pockets. Cleaners and protectors cause compatibility issues, often after macOS updates. Commercial VPNs claim to hide your browsing activity from websites, and while that may be true those VPN providers just sell your browsing data to others and the software itself slows down your internet connection and may cause syncing issues with cloud-based services. Antivirus software is simply not needed on Macs, period. For the user, all of these types of software offer only harm…and if that is limited to harm to your bank account, then count yourself lucky. If you have installed such software, follow the developer’s instructions to completely uninstall it (note that some developers fail to provide instructions and their software installs can be pervasive, meaning the only way to truly remove it is to erase your Mac, reinstall macOS then restore your user files from a backup). 

Regarding Chrome, it is a notorious resource hog on Macs. Installing it also installs multiple ‘helpers’ from Google that run in the background, and their purpose is not to help you but to help Google (keep in mind that Google’s primary source of revenue is using your data to drive targeted advertising). Even if you aren’t running the Chrome app, those system extensions are always running in the background. I’d recommend deleting Chrome and all related components.

https://chromeisbad.com

If you are looking for something other than Safari, consider Firefox or Helium (the latter is based on Chrome code but without the Google baggage). 

If those initial steps above do not correct the issue, then see if the problem is present when you boot in safe mode. That process performs some system cleanup and clears caches, and also disables 3rd party extensions that may cause problems.

Start up your Mac in safe mode - Apple Support

If that does not correct the issue, test in a new user account. A newly-created user account will have all settings at default, and if the issue does not occur in that new account then it provides guidance on what may need to be changed to correct the issue.

Add a user or group on Mac - Apple Support

Once the testing is complete, the new account can easily be deleted.

Delete a user or group on Mac – Apple Support

Those steps will help to isolate the problem.

It might help to download and run EtreCheck, written by a long-time forum member. The free version is fine. Post the full report using the Additional Text button. No personal information is revealed. 

drrichard wrote:

Thank you. I will try that. Is there an app that tells you which app which app just id an action? I have trie Activity Monitor but it tells you who is active, not who just did something.

The Console app.

Console User Guide - Apple Support

Thank you. I will try that. Is there an app that tells you which app which app just id an action? I have trie Activity Monitor but it tells you who is active, not who just did something.