Thank you for reaching out. I can certainly understand your concern with the watch asking you if your want to use the mobile network and I would be happy to look into this further for you. In order to provide you with the best troubleshooting, are you pairing your watch via Bluetooth through the wearables app and still experiencing these symptoms?
Is your phone within the Bluetooth range to be able to connect when you are experiencing these symptoms?
The only way the watch has been able to make an outgoing call over the Bluetooth connection is if LTE is set to Always Off, which obviously isn't ideal.
It seems like the watch is ignoring the Bluetooth connection for outgoing calls if LTE is set to Auto or Always On.
The expected behavior and behavior I experienced on my previous Watch 5 LTE 44mm was when it was set to LTE Auto it would always prefer the Bluetooth connection for calls which would also allow the ability to switch the call between the phone and watch with full controls available on the phone as well (speaker phone, mute, etc).
And when you're out of Bluetooth range of the phone the watch will make the call over LTE.