I have an extension that shows me the Opening and closing tags of the selected HTML element. Recently, however, the HTML tags of all the selected type are being surrounded by a square box that makes this extension useless. How do I change this? Is it the theme I am using?
This has happened because you have downloaded a VS Code extension that highlights HTML tags.
To fix this go through all the extensions that are to do with HTML and JSX and remove them one by one through process of elimination.
Once those highlights are gone then you can slowly download the extensions that were not causing the issue.