On-Screen Keyboard Input lag after loading

Hello everyone

I had this issue since long time.

When I play WoW Classic and want to write something in the chat, I press Xbox+X or PS+Square or Steam+X (I tried it with all controllers even the new steam controller) to load the on-screen keyboard. Then it shows the keyboard however I can't click on anything until few seconds later.

This doesn't happen outside the game. If anyone faced this issue and solved it, please share your solution.

Thanks