[bryanrasmussen]

I'm pretty sure that every time Netflix thinks I did not see an episode all the way to the end it's because I skipped out just before credits, or just the second credits started, or I accidentally started over and then Netflix thinks I have that whole episode to watch.

Aside from that it does seem that Netflix sometimes 'forgets' if I wait a long time to go back to something, in which case I suppose there can be some sort of cleanup going on. I mean sure I would want to keep these timestamps forever, but probably at a certain scale you want to get rid of old ones as much as it might annoy me.

[ghusbands]

No, with both Netflix and Prime Video, if you cancel the skip-end-credits-to-next-episode (either intentionally or by configuration) and watch the credits and then close the browser, the next time you tell it to continue that series, it'll start from the start of the episode you've just watched. (At least when watching in Chrome on Windows over the past year.) Given that failure, it would be entirely unsurprising to see other bugs in the progress-tracking.