Calling from Android to Linux works only with one of two accounts.
I have two accounts on Linux (account A and account B). If I call account A with an account C from my Android smartphone, it works. If I call account B with the same account C, as soon as the call reaches the state "ringing" it ends with the message that a call was missed. This message is only shown on Android (account C), not on Linux (account B). Of coures I checked if account A, B and C are online and they are.
The main difference between A and B that I know is that in B I have changed the "Allow calls from unknown contancts" and "Answer calls automatically" settings for testing purpose - but I changed them to "Allow calls from unknown contancts" = true and "Answer calls automatically" = false.
On Android I'm using the latest F-Droid version 20200810-01. On Linux (Manjaro) I'm using a selfcompiled version, compiled on 20200818.