I agree with Miriam. I think you'll find that "Servicing" the tensioner is going to fix both problems. If the tensioner as a whole is moving, it's likely sitting too far toward you as well, which means the pin on the back isn't far enough back to get pushed by the presser bar lever when you raise it.
There's a set screw, inside the door that holds the whole tensioner in.
I guess I should try to do that upper tensioner service tutorial sooner rather than later.
Thanks Joe, I think I knew to do what you mentioned, but for some reason it hadn't filtered into my consciousness yet. I have the same problem with a 301 here. The only issue outstanding on it. I was just using painters tape til I "remembered" what to do.