Gmail issue / No longer able to add all my Gmails to apple devices email
Does anyone know or have encountered problems of adding your Gmail to your apple device email? I tried but cannot seem to add my Gmail to my iPhone and Mac. Someone linked old numbers I used to own at one point but no longer used, onto those emails I'm trying to add. They linked it as a 2-way verification where even if I know both my password credentials and have my current phone I still cannot access. Google is almost like a joke with their customer support. You might as well be literally left to your own "devices!"
I've tried googling this issue, especially with phone numbers linked that should not be but didn't get much luck.
I cannot use the App Password either as it does not work. I do not want to go through the Apples App for Gmail to add a Gmail. I am wondering why this has happened as at one point, I was able to add my all my Gmails to my Apple emails.
If there is an interference, who is blocking this? Is it Apple, Is it Google? As at one point, adding my email address was not an issue.
iPhone 12