fair enough, thanks for the quick reply and clarifying this @Daniele_Sunrise - I just wish someone in Sunrise support had mentioned the lack of official support a little earlier, I spent definitely too much time waiting in the line lately.
based on the lack of capacity/interest from sunrise to dig further and the following info from Fairphone: Their support has logged this carrier configuration behaviour with their internal network team to investige the initialization of the IMS and SMSC (Short Message Service Center) settings.
However, they did not promise, if a fix is likely or can be high priority at the moment. That, sadly, is imho also fair enough, considering the longevity (we made it to the 5th year, yey!) and forward compatibility is the really tough part of their mission. For the time being they suggest to try living with the workaround we found here, reapplying sunrise configration, esim reprovisioning, physical sim, or moving to another network provider.
Since we have tried all these options here and I’m not tolerant enough to live with the workaround, I have to try my luck with another carrier next.
dear all in this thread 🙂 - it was a very nice experience not to be alone on the quest. feel free to send me a private message regarding the other carrier test (I prefer not to misuse sunrise’s community for discussing other carriers). 👋