As for all the thumb drives and statements of what ‘should’ work, I’ve been through about 5 or so thumb drives. I even ordered a new
Samsung 256GB FIT Plus USB 3.1 Gen 2 Type-A Flash Drive which had the best reviews and likelihood to work.
The drive worked fine everywhere EXCEPT in my late 2017 Model S 100D. Oddly enough, I had some really old thumb drives (1 Gb) which did work for a while but it seems the constant writes to the drives wore them out. They additionally weren’t large enough for any real day-to-day use.
I finally did exactly what you did and put a SSD in a USB case and have had that in my care for about 6 months. It is 450 Gb so nice and large and seems to function nicely with TeslaCam. The only thing is it takes up more space in the USB well. I may figure out another place for it but for now it works and I get recorded Sentry clips regularly.