I've had this problem already in the past, but now are quite a few plugins affected.
See attached screenshot.
None of the plugins find and load their standard presets (or banks) even if they are there, and loading manually ...
After I updated to 12.5.1 today the scan completes and picks up the 3rd party plugins but when I close and reopen the plugin manager they are gone. My old projects that already have the plugins loaded still work btw ...