cgsecurity.org

This is a PNY 115gb flash drive, no partition, bad boot sector etc with running testdisk in various partition formats,,, so I have now
ran it multiple times with photorec … it runs for about an hour or so and then kicks out with
the same 21 files recovered. I thought it might be background programs causing this Kickout - windows 10 edge screen popup "directory name invalid") but even with an msconfig shutdown of the background programs … it just did it again, only a little sooner than with the bg programs running …. thanks in advance in what to try next!

Can you run Windows 10 in safe mode and try the latest PhotoRec 7.2-WIP ?
Do you have the same problem ?

Yes, kicked out earlier in that mode. I tried to run it with zar x last night and it ran for almost 16 hours … then kicked out. Perhaps that can give someone a clue. There appears to be data there … but how to access it? It crossed my mind that it could be a momentary contact hardware issue where the contact disengages momentarily … and the software does/cannot resync ? Is that plausible?

Try to clone the disk using ddrescue as described in https://www.cgsecurity.org/testdisk.pdf
Once it's done, remove the original disk and try photorec on the image file. When using PhotoRec, choose [Whole] instead of [Free].