I found the same "spring back" problem a few months ago, sometime after upgrading to OS 11...along with a few other minor but nagging and stupid flaws, and *one simple temporary solution:
- After moving, copying, renaming, aliasing, or changing tags for files within the same Finder window of a USB drive, the Finder starts getting screwey. I get the 'processing' icon or whatever it's called (small circle of radiating lines, not the "beach ball") and it may or may not recover. This does not happen in other Finder windows currently up...until I build up a workload in them.
- Finder starts failing to display contents of my USB drives (making me think I've lost gigabytes of data), with my data drive sometimes crashing and deleting the shortcuts in my sidebar. It may take a few Finder restarts or even a Computer reboot to clear it up and get back to normal.
- Finder starts bogging down and eventually crashes...if I don't restart it myself.
*I have found one way to clear these up, and possibly other Finder flaws: 'launder' the Finder window. When the window starts bogging down, I click on my internal OS drive for a few seconds, and then use the back button to go back where I was in the USB drive, and everything is peachy keen...for an indeterminate time.
Perhaps other solutions described here temporarily clear up whatever processing errors are building up...though with more effort. I'd like to hear why these work.
Also, when pasting into TextEdit, a huge block of blank text appears in from of the pasted text. It's like a giant tab, and is deleted by one keystroke...but I switched back to an older version of TextEdit to avoid it. (There's an entry on this elsewhere in Apple Discussions.) Also, sometimes the keystroke for copy does not work, and I must use a right click. This especially happens with web text, especially with MS web apps. I don't know if 'laundering' Finder helps this.
And I hate that aliases don't display icons any more, since maybe OS 10.10. This has ruined years of cross-referencing thousands of images.
I also have catastrophic problems in my third-party Graphic Converter...which they fix with an update...until Apple makes another update.
None of these have been fixed in later upgrades, even to OS 12. Come on, Apple, I've been with you since my beige 1996 G3, and you had me in 1993 with a Classic Mac...
[ Late-2014 Mac mini, OS 11 to 12.1. Desktops will never die. ]