I am looking at the following case:

• I start the language server, it runs the validation, and adds a bunch of warnings/errors on my source files (all great)
• I close all the editors, the errors and warnings stay around (makes sense)
• The language server is shutdown being the scenes, the errors and warnings stay around (makes sense, too)
• I open the preferences and switch the errors/warnings off because I want to get rid of them - BUT THIS DOESN'T REMOVE OR CHANGE THE EXISTING ERRORS/WARNINGS. They stay around.

The reason for this is obvious (the language server is not running to take the new preferences into account and update the errors/warnings). When I startup the language server, it reconciles everything and the errors/warnings are gone (for my case described above).

But it might probably not make a lot of sense to the user that the errors/warnings wait for the language server to kick-in before they get removed (due to my changed preferences).