I'm just writing up a Joplin behaviour that I found surprising in case it helps anyone else.
I noticed some missing text in some of my notes and went investigating. Turns out there had been conflicts when syncing those pages between the mobile app and the desktop app. Now, I had expected the Conflicts notebook to show up on the desktop app (which is where I tend to organise my notes; the mobile app is usually for data entry only) and make visible that I had a conflict to resolve. But actually, the Conflicts notebook stayed local to the mobile app where I didn't notice it.
I guess I can understand this - syncing the Conflicts notebook might create more opportunity for more conflicts, and then what do you do with those?
Perhaps a useful feature would be to flag in all linked instances of Joplin when any instance has any conflicts?