The native Android client just can’t do two way sync. Just put a text file or something into any folder (from the web or desktop). Now sync that folder to Android. Now edit it on the web/desktop, and look for the changes on Android (without actively telling it to “sync”). Then change the file on Android, these 2nd changes are never sent back to the server unless you explicitly tell it to “sync” again, manually. That’s what I mean with 2 way sync.
There are quite a few files where you just need that to work to use them properly, like the database of a password manager as a prime example. Mine can talk to Nextcloud natively, so I don’t need the client for that, but I was incredibly close to just switching to syncthing, if I didn’t have active users that use the web office integration of Nextcloud.
Yeah I was just so confused when I found out that this isn’t possible. Like, it’s a file hosting and sync-ing application. That’s like absolute basics. It isn’t even “just” an open source project any more, there’s a company behind this product now. I am the last person to be angry about an open source project, run by a volunteer or three, not being feature complete.
For what it’s worth I think it works in the iOS version of the app (possibly always has?). But that’s doesn’t exactly help me either.