Hello,
I haven't had a response from 3CX but I wanted to provide a response for other members of the community who might come across this. The issue appears to have resolved itself, and 3CX has released the final version of V20.0 Update 2 (Build 715 Release) which I ran this morning, which appears to have completely fixed the issues on both Android and Android. on iPhone. The only problem that persisted was that on my Android I received the call twice, that is to say on the "3CX" application and on the "Phone" application. On the "3CX" application, the call arrived authenticated but on the "Phone" application, the call arrived as "unknown" and of course it was this notification that took over. So I found a way to modify this setting in the "3CX" application. You have to go to the status settings via the little pencil and uncheck the "Make my mobile ring simultaneously" option. However, this option was not activated in my user's profile when I checked on the admin console. This is if this information can be useful to anyone else...
BR,