Can't login via iPhone

I’m able to login on my desktop (Mac) but my login fails repeatedly when I try to login to the app on my iPhone. Message reads that either my username or password is incorrect. I’m using the very same login info as on my desktop. I don’t want to change my password, it doesn’t help to do that. Any suggestions on how to get past this trouble.

What for an hour and try again. Their servers might be overwhelmed.