are you using a custom launcher?

 

That is an oddity, and it only affects some but not all icons. When you look in your Settings >> Apps menu, is there a 'Moto App Launcher' app? Look in its 'Storage' menu and tap on the 'Clear data' button, then restart your phone (again) and see if that makes any difference.

 

That's why I stated you use 'Clear data' as opposed to 'Clear cache', but its still not a definitive solution, just a guess that the launcher is the source of the problem.

 

also maybe try a different launcher. on my z fold 3, i hate OneUI which is samsung's own launcher. i instead use Nova launcher...been using it for many years now with no issues at all. it is small in size and will not drain your battery.

https://play.google.com/store/apps/details?id=com.teslacoilsw.launcher

 

That is unfortunate, but I'm not sure there are other, viable options in this instance. There was a corrupt config file buried in some obscure directory, and actually finding where and which one would involve a lot of time and effort.
But time will tell, let's hope that did solve the problem and it doesn't return.