Photos sometimes get an invalid filename

From time to time I notice my automatic photo backup solution (via Nextcloud client) fails to backup a specific photo. Each time it fails, there’s a '\' (backslash) at the end of the timestamp in the filename, which obviously should not be there.
For example, a valid filename for a photo looks like this:
However, sometimes the filename looks like this instead:
As soon as I manually rename the file (removing the backslash), the backup works fine.
I’ve been using the Nextcloud client for many years now on several different phones, and I’ve never exprienced this problem before. So I’m suspecting the camera app of the FP3+ doing something fishy under certain circumstances.
Has anyone run into this problem before? Any suggestions on debugging this are of course welcome as well.

A post was merged into an existing topic: FP3 Camera File Names including “”?