Alt+X does not work, occasionally

Problem

Samarth observed:

There is a minor issue when I am reading and trying to extract text. Sometimes alt + x doesn't work. I close SuperMemo and open it again to check. It solves the issue sometimes, but now it became frequent. Is there any fix for alt x not working frequently?

My System is running on Windows 10. 32 GB Ram Nvidia Graphic Card Intel i7

Comment

This is first report of this kind. If you make a selection in HTML in a topic and press Alt+X the result should be an extract. Hard to say what might be causing this to not work. Keyboard problem?

Suggestion

It might depend on a specific page: 1. please send HTML (Ctrl+Shift+F6) 2. use filter (F6) to get rid of pesky code (if this is the case)