
Does anyone know what is happening?
My guess would be that you’re running a Linter of some sort that’s trying to give you hints on code quality.
I remember it started to happen when I updated sublime text to the latest version. Do you have any other suggestion?
Sublime will wrap text in white boxes like that if you have the Highlight Matches option turned on in the Find panel, but it doesn’t draw markers in the margin that associate with them. So I would say that this definitely seems like some sort of third party plugin or package doing something for you. Are you sure that a package you were already using didn’t also upgrade itself? Does the status bar say anything while the boxes are showing?