Hello Does anyone else know the problem? My smartphone S23 cannot do wifi calling with my Sunrise provider. It simply has the wrong firmware. It must be the Open Market version released for Switzerland. This can be recognised as follows. Example: CSC: G930FAUT1BPH1 The AUT is important here. But my smartphone has CSC: S911BOXM3AWF7. Here is the text from my supplier: If you have a Samsung device, please note that you can only use Wi-Fi Calling with the Swiss Open Market firmware. You can check this as follows: 1. enter *#1234#. 2. after entering, you will receive automated feedback on the firmware version. 3. You can recognise the Swiss Open Market version by the following abbreviation "AUT": AP: G930FXXU1BPLB / CP: G930FXXU1BPJJ / CSC: G930FAUT1BPH1 If you receive a different code as a response, you unfortunately cannot currently use Wi-Fi Calling.