[JimDabell]

SMS 2FA often blacklist VOIP and similar systems to avoid abuse. Try receiving SMS 2FA at a Twilio number, for instance – it’s super unreliable. There are virtually no providers where you can reliable receive 2FA via SMS programmatically, with the exception of a handful of companies who use large banks of real SIM cards.

[janfromdaito]

Twilio has a whole support article on why you probably don't receive certain SMS messages: https://support.twilio.com/hc/en-us/articles/223133447-Not-R...