Update caused encryption disabled

On my android 9 / emui 9.1.0 device, after updating to Joplin 1.1.2 (I guess from 1.1.1?) on the 21st September, Joplin lost connection to Dropbox and turned encryption off.

Why would that happen?

What is the best way to re-establish encrypted sync?

I thought I fixed this by reconnecting my joplin app with dropbox.

However, after dropbox was updated on my phone (now at version 208.2.4), Joplin (still at 1.1.2) suddenly asks me to enter the passphrase to decrypt notes. When loooking in the settings, the sync was disabled which makes me think that the dropbox update reset all app tokens.

However there's still a problem with joplin, as in spite of having entered the master key, and in spite of having connected to the same dropbox area that I'm connecting to from my PC, the phone app says encryption is disabled. I verified that recent notes in dropbox are unencrypted.

Encryption is enabled on PC. In the app, if I press 'Enable encryption', I'm asked to create a new master key. Shouldn't encryption turn on by default when I enter a master key?

Isn’t it the same problem as this one? Webdav config / encryption config randomly lost on Android

Yes, thank you! That is a better description of my problem.