Im running the joplin app on an update to date pixel 3 and trying to sync it with nextcloud. The desktop app syncs with my nextcloud so I am assuming the path and credentials are valid. If use the check synchronization button it will stay on “Checking… Please wait”. If I force close the app and initiate a manual sync it will never complete, if I click cancel sync it will say “cancelling…” until i force close the app. Anecdotally I feel like its an issue with cached data from awhile back when I gave joplin a try because I noticed that after updating my next cloud sync credentials and url(than saving) they reverted back to the old credentials after I uninstalled the app and reinstalled it.
Here is a pastebin to my sync debug file https://pastebin.com/vvRECTKu