Not just locally on the device! There must be an error when calling or texting the number.
Data must work for internet for Signal, VoIP, etc.
This is for a UK PAYG SIM.
There should be no way for anyone to demand my number, or for me to leak it, or doing so should be irrelevant as it does not work.
Don’t give people your phone number. Afaik signal now works without it.
As a downside, you may find you are not as important for these other people as you think, people are under no obligation to accept you forcing your quirks on them.