If you switch this setting it messes with .htaccess file. I would suggest to backup it with working settings and then delete it completely. Then set the required settings in BO.
If this does not work try clearing all caches - 2 TB caches, manually all your theme cache files and smarty files and if you have some serverside caching enabled it too. Refresh couple of times or try new browser or incognito mode.
Some combination of those items should solve your issue 😉