Synchronization seems to be completely broken, and I just lost my entire database and all subscriptions. I am self-hosting Nextcloud with Gpoddersync and I wanted to have Kasts for Desktop and Antennapod for Android. Every time you unsubscribe from a show, syncing puts it back on your Antennapod because it is never deleted from the database. Uninstalling Gpoddersync from Nextcloud does not clear the database. I went through and manually removed every subscription from the Gpoddersync web page and when I synced fresh with Antennapod, it deleted all my subscriptions, queue, and history. There is no apparent way to make Antennapod’s local database the source of truth to push to the server.
I luckily had a database backup from March 18th, but it means I lost 13 days of listening history. The sync feature is dangerous to have and worse than not existing since it not only doesn’t work but it can completely delete your setup.