Hi Vivian,
I'm Sumit, here to answer your query at the Microsoft Community.
The white boxes appear if the item is selected from the keyboard using a key. I think a key is being pressed together with buttons.
Please check Keyboard Tester, and see if a key is being pressed, when you press esc etc.
https://www.keyboardtester.com/
Keep us posted.
Disclaimer:
The link included is a non-Microsoft website that would provide accurate and safe information. Watch out for ads on the site that are frequently classified as PUP (Potentially Unwanted Products). There is no need to buy paid products to fix your computers as they sometimes do more harm than good.