A quick fix for decryption issues. If you have used earlier betas, after upgrading, remove your account on every device with monal (iOS and Mac) and re-add it. There was a bug in earlier betas that messed up the signal session and a clean slate should help a lot.
Syncing messages between two Monal clients on my side does not work with current beta.
Is the issue decryption errors or that the messages don’t show up?
They don’t show up at all.