If you open up the media queries screen (icon to the left of the tabs) you will see an option to load a media query set. Choose the “Beaver Builder MQs” option. And if you haven’t already added styles to MT’s default media queries, set the “Overwrite your existing media queries?” option below “Yes”. Otherwise set it to “No”.
By doing this, MT’s media queries will sync up with your current BB breakpoint settings, even if you have changed the BB default breakpoints.
I hope that helps. Please let me know if you need further assistance.