pseudo-damaged files & programs after restore Monterey

Monterey 12.6.2, MacBook Pro 15,2 with touchbar.

All these troubles began after I booted to recovery, erased my internal SSD, reinstalled a newly downloaded copy of Monterey 12.6.2, booted up, and migrated all my files using Migration Utility (method recommended by prompts within Recovery).

I now have hundreds of "damaged" files that are not really damaged. For example, mp4 files created with Handbrake that formerly played in VLC when I double clicked them (the files were on an external GUID/HFS+ volume) now pop-up a damaged error window with a default invitation to delete the file.

This is so wrong and amazing. The file is not damaged. All it wants is to be opened a different way. (!)

After reading another thread here, I deleted the VLC program. I downloaded a new version after emptying trash. The .dmg file containing the new VLC gives the SAME type of error message as the mp4s.

I "restored" VLC from a Time Machine backup.

If I launch the restored VLC, and drag the allegedly damaged file into its main window it plays just fine.

So my computer is lying to me, and asking me to throw away good files. Also, it is refusing to open .zip files, an activity not related a manner I can understand to refusing to open .mp4 files, each time defaulting to a proposed action of deleting the files.

This is reminescent of 1990s adventures with operating systems from Apple's then main competitor.

Suggestions? Please don't refer me to help for VLC. This is a MacOS problem. Recall the .dmg file.