I have been aware of an issue with the Menu not working on a mobile device. Unfortunately, I’m not too experienced with WordPress having grown up with Mambo & Joomla, but having been prompted (again) about the issue, I did a search (Ain’t Google and DuckDuckGo wonderful) and was able to find the solution. Turns out a WP plugin affecting the cache was to blame, disabling any such plugins resolved the issue.