FP3+ user here. I have a similar issue, photos are not synced to cloud service for a few releases. My original 0.16 worked fine, some update after that broke things. 0.19 and now 0.20 does not work. Not sure about 0.17, 0.18.
I have only two accounts listed on /e-settings, though.
Thanks, Pete, yes, I already have an e/cloud/ account. This brings more clarity to the subject, I will check out how things work with the NextCloud app, thanks again.