Why is there a black semi-opaque box appearing when I type?

[Android Central Question]

I have the Xiaomi Mi 9 and this morning when I woke up, whenever I press a letter on the keyboard (regardless of which app I use), I get a black semi-opaque box hovering over the key I just pressed. How do I go back to what it was originally?
Thanks

 

[SpookDroid]

Using the stock keyboard or a 3rd party one? Have you checked to see if you have the option for key pop-ups enabled (not sure if it's an option on the stock one, it is on keyboards like Swiftkey). Any themes you might have applied that might be 'hiding' the symbol pop up contents because of background vs text contrast (or lack thereof)? What about changing the long-press sensitivity time?