Sorry to hear you are having this issue. We will investigate it but in the meantime any error message both on server side and on browser console will help a lot for us to pinpoint the cause of the issue. Also which version of WordPress and PHP are your server is in?
The PHP version is 7.3 and WordPress is 5.5.1, as its a production site we are trying to rectify the situation asap. No browser errors shown, the WP Mobile Menu plugin displays the menu hamburger icon but it won’t allow the menu to open, disabling the WP Table Builder plugin allows it to work again. We were also seeing unpredictable table rendering with mobile devices, mainly ipad and iphone, where the last column rows expanded down the table one letter at a time irrespective of table sizing or automatic responsive settings.