hey there! i had been facing the same issue too, i have a main org email (tech@myorg.com) and my personal email which was added via org email. i cant connect my github acc via my org’s email and also my personal email requires credit card though i have added one on my org’s email another issue i had been facing on the org’s email was email verification, i havent been receiving any email for verification even though i tried resending it.
for more context the org email uses email (proton.me) password auth and my personal email uses my github oauth