Hi Today I see this and I don't know how can I fix it
This comes from WP theme or from some plugin. wpForo doesn't have such classes in menu. Please try do deactivate all plugins one by one and check after each deactivation.
Also leave some URL to allow us inspect HTML conflicts.
That's not coming directly from wpForo, and as far as I know it's not a standard feature of vantage theme you use. It looks like you've installed a mobile nav plugin, I'm not sure how it works but make sure that menu isn't sharing the same menu/theme location as the main menu. You should find and correctly configure all Mobile Nav related plugins you have. Or just deactivate those.