Discord's phone verification is awful. They are using some super old database of what provider is associated with your phone number. I ported a Google Voice number to Verizon and they said I can't use it for phone verification because it's Grand Central, a company that went out of business before Discord even came into existence.

I pay them $99 a year, and their customer service treated me like shit for this. What do I care if someone hacks my account and destroys the large community that I moderate? That's their problem, not mine. But I doubt they care.