Yup - the numbers Google Voice has are tagged as 'VoIP numbers' in some dataset somewhere and are blacklisted by a fair number of services and blocked from 2FA

Yup - the numbers Google Voice has are tagged as 'VoIP numbers' in some dataset somewhere and are blacklisted by a fair number of services and blocked from 2FA or Sign-up. This has also happened to me when using MVNO carriers (Cricket, for example).