Did you find a solution? I have the same issue, that incoming calls get directly forwarded to the mailbox. I can call people without any issue.
I contacted the support and they even checked the log files from their app. But they told me they found nothing and that I am the only one who reporteted that issue.
Answer Satellite Support in german:
aktuell lässt sich für uns nicht klären, wo genau der Fehler zustande kommt. Wir haben auch noch keine anderen Meldungen dazu erhalten und warten jetzt ab, ob sich das Problem häuft. Vielleicht erkennen wir dann, welche Stellschraube wir nochmal festziehen müssen. Ich danke dir in jedem Fall, dass du das Problem gemeldet hast!
Translated with Deepl
We are currently unable to clarify where exactly the error is occurring. We have not yet received any other reports and are now waiting to see whether the problem has become more frequent. Perhaps we will then be able to see which adjustment screw we need to tighten again. In any case, thank you for reporting the problem!