Occ files:scan - does it include dropbox? could it affect ability for media player to play a video

I ran occ files:scan. It seemed to be taking a long time. I then realised I have a link to my dropbox file repository using the External Storage: Dropbox app and it seems that occ is scanning all the files through that link. Is this expected? Is it a problem apart from the fact that it took an hour to scan and still hadn’t finished. Is there any way to exclude that in the scan?

Corollary question: I added a .MOV file to the files folder manually (the reason for running the files:scan in the first place). The file does appear on the UI now, suggesting that it was scanned by files:scan before I terminated it. When I click on this file though, instead of playing in the media player, it links for download. Might this be because my server doesn’t support playing mov files? A quick google of that issue suggests that the symptom would be that the media player should open in such a case but report the file is of a type it cannot play. So I am wondering if perhaps the files:scan has to complete before the file is correctly recognised or something like that?

Just tried again and the file now plays in media player. So, not sure what that was about. Still interested in the question about dropbox though.