Game freezes when pressing "r" in a textbox (Chat or Commandblock GUI)

Typing the letter "r" in a textbox, either chat or commandblock gui, freezes the game and it also unfocuses the textbox! You have manually click the textbox again to continue typing.

 

I am using a QWERTZ Keyboard, and the language in Minecraft is set to English US. But it doesn't really matter because even if the language is German the same problem occurs.

 

UPDATE:

Same problem appears with a Surface Pro when typing "r" in a command like this: /execute @e[type=armor_stand] -> it freezes at both "r".

 

Here is a HD video of it:

https://youtu.be/CXHJdptyBEQ