Hovering

How to stop a pointer hovering over an icon from auto-opening the icon.

Take a look at Folder Options, maybe there is a setting there.

Thanks glasskuter. The box was unchecked, but the only time it happens is when it hovers over the red X close button. After a few seconds, the window closes.

Probably sounds weird, but have you per chance tried another mouse, preferably a cheap corded one to test with.
Here are things I would try.

1. Make sure you have no corrupt system files that is causing this problem. Open a command prompt as administrator and type sfc /scannow
Pay attention to the scan results to see if SFC found anything it could not repair. If it found corruption it could not fix followup with this command (note the spaces)
dism /online /cleanup-image /restorehealth
Restart computer

2. Perform a clean boot to eliminate software conflict causing the issue. If it doesn't happen in a clean boot, you have some software conflicting with Windows. Brink's procedure will help you weed out which one. Perform a Clean Boot in Windows 11 to Troubleshoot Software Conflicts Tutorial

3. See if it happend in safe mode.

4. Repair Install Windows 11 Repair Install Windows 11 with an In-place Upgrade Tutorial