If that's true, that's wack. There's no reason that the one phone company's service issue should have affected your phone's ability to call 911. Towers aren't company specific so it doesn't make sense that there would be interference 🤔 someone fucked up
Did you actually dial 911? Because if you tried dialing 911 and it didn't go through, that's a problem. ALL phones must be able to dial 911, even without service. If the phone can hit a tower, it can call 911.