I don't have a solution but I can confirm this behavior.In emacs 24.5, the "Point to Register" prompt disappears after pressing "1".In emacs 25.x, the prompt stays there after pressing "1".I tried edebugging in both 24.5 and 25.x but the behavior looks the same when doing edebug (the prompt disappears).I briefly looked at the register.el, but couldn't spot any change there that could be causing this. So the change is probably in some common library in elisp/C.--
Kaushal Modi