Julius

Umfriend and amateurphotographer, I don't know what your ages are, but I'm 52 and been using computers to store data for about 36 years now, and let me just throw this in here;
The times when I 'accidentally' deleted a file or files and lost them that way can be counted on one hand. Especially since we have the RECYCLE BIN or Trash can that problem has disappeared for me, if I even ever accidentally do hit delete (in TotalCommander or DxO Photolab or some other program) and confirm its deletion, because the confirmation is still not automatic for me. So, I don't know about you guys, but that barely ever happens, if at all, in life.
What *did* happen a lot more in the past 36 years is storage media suddenly deciding to crap out on me , floppies or drives becoming entirely or partly inaccessible. I've even lost 16 GB of stored data when an at the time very expensive Intel SLC SSD decided to stop working a few years back, it went from 1 to 0. No software out there could get it back, not even SpinRite, probably a charged spark borked the controller chip. Luckily it was mostly an OS installed boot-drive, but even so, it warned me about not trusting on the high MTBF of SSDs too much.
What makes backup policies suck the most for me is the fact that they're almost always dated or too old, not current or not current enough. HDDs or SSDs breaking down almost always happens at moments you least hoped they would, and in ways you never expect. This, for me, is where DrivePool comes in. It has already saved me from losing data several times by having a direct dual or tripple written down copy of what I was working on. These days I have big data passing through my storage media, and it's really comforting to know I can access the functional left-over storage whenever one or more stop working. RAID storage methods for redundancy are horribly overrated, in my experience. Oh the times I've tried to restore data from broken RAID-arrays probably outnumbers those for just broken disks, and the time it took, good grief, incomparable to having StableBit DrivePool create standalone copies.
So, backup or not, for me backup policies only exist in order to have data off-site and/or offline.

Have you considered it may not be the flash-drive that's causing this? Try the USB controller or the motherboard. Especially check if the board gets enough power. I've seen USB drives unjustifiably getting the blame for issues more often than I can count, while a mainboard was broken, or PSU didn't have enough power left for the USB lanes.
If that's ruled out, and it still fails, try running SpinRite level 2 scan on the USB-drive (or similar software). May work wonders.