Broken catalog connections due to One Drive

On returning from a cruise, we were surprised to find all of my wife's photo files numbering more than 80,000 pictures and 670 GB of files were no longer where we had them stored on a dedicated mechanical 3 TB hard drive in RAID 1 ( K:).  Upon investigation, we found they had been migrated to C: (the SSD boot drive, RAID  1) in the One Drive folder.  Not only did it fill all but 5GB of the 1 TB drive,  it moved all of the files outside of the Adobe Photoshop Elements program, thus breaking the catalog connections, that had taken her thousands of hours of taging, face recognition, album creation, renaming, and manual dating to accomplish across 6 catalogs.  I am sure this migration of files did not happen overnight.  I am assuming that this migration was made possible by Microsoft with the advent of Windows 10 & 11 and with the move to the subscription model for MS Office in Microsoft 365.  The good news is that the photo files appear to be all there.  I am at a complete loss as to how to attempt a recovery.  I have a dedicated NAS that does a weekly incremental backup of all of our computers, but assume that this backup will be virtually useless as it is capturing the incremental decreases of the files that need to be restored.  I want my photo files all back on my K drive.  I want them reattached to the 6 catalogs they were connected to, and all of the data connected at the file level.

I am hopeful that someone else has either been through this and has a simple solution to recommend, or has in depth product knowledge with which to guide me through the steps that I will need to take for even a less than perfect solution.  Any and all solutions will be greatly appreciated.  Thanks in advance for sharing your knowledge, experience and wisdom.