Photoshop: Alt key won't unfocus menu bar when released which causes a system sound für every key

[el-berto]

I've just updated to Windows 10 and I am now experiencing a strange problem:

When I press the Alt button it sets focus to the menu bar (File, Edit, etc.), but when I release the Alt key, the focus won't switch back, so any button pressed after that either opens a menu or triggers an system sound (for example is space bar is pressed to move the picture).

This drives me mad. 

I have checked if sticky keys are active: everything is deactivated.

In Lightroom Classic the Alt key behaves different (normal): If it is pressed, it switches the focus to the menu bar, when the Alt key is released the focus is gone and back on the image.

Any idea how to solve this? 

[Guest]

Just hit the Alt key again