Welcome to the forum @FrancYescO
While no response came here, I asked about success on the GitHub issue, and got:
[Dropbox oauth] expired_access_token error from Dropbox short-lived access tokens #4667
I just installed 2.0.6.102 and was able to successfully run a new dropbox backup!
but I don’t know where that leaves things. Is it possible that this only fails in Docker?
If someone wants to head over to GitHub, maybe you can look for any differences…