So it could be a few things doing this. One wifi calling being on could do this, ever since they did the wifi calling optimization bull **bleep** this has been a issue. If your wifi calling is on and your phone decided it was best to prefer cellular over wifi your calls and messages won't send or receive. But also I have noticed the inconsistent signal fluctuations on cellular and sometimes even the complete loss of service has started to become a issue. I have bought Samsung devices ever since I had the note 4 and I have had no problems but since I got my note 20 ultra 5g I have had problems with loss of service or signal fluctuation. I am getting frustrated with it now. Or when I have almost full 5g but every time I open chrome or YouTube it says no internet connection. And the auto switching wifi calling preference optimization bull has not been helpful on top of it. I have been frustrated with this device ever since I got it. It's been one thing after another. I have been having issues with wifi calling, signal fluctuations, no signal issues, screen mirroring through Samsung smart things ( Grey screen), touch screen inconsistencies, Bluetooth issues, charging port moisture issues, apps crashing, problems with the auto switching between 5g and 4g and good data signal until I go to use data than I completely loose signal. That among other things like voice to text **bleep** now, it can't understand what is being said and has a problem with punctuation being spelt out instead of adding the punctuation. Also has a problem with delayed text or no text displaying when using speak to text. Among other issues and I have tried countless options or settings to no avail.
