I am encountering the same issue described in an older thread : when I tap on an EditText to type into it, I get exactly the same result as the picture here :
A large bubble over the keyboard, and a small button on the right, which says "next" if several EditText are on the screen, and "Done" when it is the last one.
I am not so sure it is Android bug : it does not manifest with other apps. Could it be a feature, that needs to be turned off to make sure to edit in the layout ?