Do you have (good) Internet-Access with your Smartphone?
Can you make some tests (with WiFi switched off of course) in all of your rooms?
And also have a look on the “reception bar” in various rooms and Network-Type-Indications like "5G/4G/3G/2G/LTE etc.)-
Background of my question:
If you have good Internet-Access but at the same time-and-place, no phone-calls are possible, then you probably don’t have VoLTE (https://en.wikipedia.org/wiki/Voice_over_LTE).
This means that your phone need to fall-back from 5G/4G to 3G/2G (i.e. to UMTS/GSM). And if there is no good 3G/2G-Infrastructure aroudn your house –> no phone-call possible.
See also my personal story with “bad to no” phone-calls in Sunrise’s mobile network: https://community.sunrise.ch/d/30675-volte-und-wifi-calling-mit-pixel-3a/8