There's been a recent tendency to split login forms into username/password over two screens as mentioned in this article. It's maddening. Password managers can't deal with this, unsurprisingly. I don't see the benefit this provides for anyone.
I wish password managers would become popular with non-tech people already. I can't wait for a day where there's just a "Sign in manually" link for the few people that manage to remember their 1200 usernames/passwords. Password managers shouldn't need to rely on autofilling inputs at all.