When syncing from Joplin Server (docker with linuxserver io swag reverse proxy), the Windows PC sync is very fast. But on Android, the decryption takes a very long time (many hours).
There are no errors, the decryption goes on, but the phone gets heated and the app UI starts to lag. This doesn't happen with Dropbox sync.
Syncing is on my local network, nothing leaves the home network.
It's not related to Joplin Server. In general encryption can be a problem on Android, it just takes time. Especially if you have many resources you might want to just let it run for a while until all decryption is done.