Hey I have exactly the Same Issue on my Pixel 8 Pro. Did you figure something out? But i dont have the ! next to the signal strength
Same carrier?
I use Congstar wich uses Telekom Infrastructure but i have a second SIM that is with Elisa in Finland wich works.
OK in that case, I am moving this to a new thread. Likely your issues are not hardware related, but instead your Access Point Name (“APN”) settings may need to be adjusted to accommodate your carrier. You can find these settings under “System Settings > Internet & network > SIMs > (your sim) > Access Point Names”. Please post your current settings for reference.
But as you don’t have the “!” that means that your cellular data is working? So this may be more complicated as your APN handles mobile data (so maybe that is correct).
Please also look at *#*#4636#*#* > Phone Information (V2) > IMS to confirm if VoLTE is available.
Thank you for trying to help but i was able to resolve this issue. For some Reason there was a Call Redirection Setup for my Phone. I never activated anything like that but it still happened.