Same thing happens when error messages push the whole form down. This is annoying when for example I log in to my bank account using 1Password. When 1Password gets focus (and the login form loses focus), the login form immediately complains with an error message saying the fields are required and pushes the form down. When I select my bank login from the 1Password dropdown, I always immediately try to click on the "Sign in" button, which at that point moves up because the error disappears.