This is a tangent; but I had a 'pwned' password that I've used for years on steam that started getting hacked like 4-5x a week; I would just ignore the 2 factor attempts for several months.

I finally changed the password to a slight variation that is not in this list (nor likely any others, 9 random alphanumerics); and within a week the two factor notifications started back up!

I was really surprised; admittedly the modification was trivial, but that is pretty thorough for a steam account I've spent like $100 in.