edit: figured it out, though seems quirky
Used to work now I get this: When I manually enter a search engine and press "Add custom search engine" I get sent to the "Adding a new search engine via the URL bar" page, showing how to add a search engine with the 3 dot menu, but the option in the 3 dot menu never appears for the sites im trying to add. just like the other guy, will also fix the rating if the issue is fixed.