WP Bakery Builder

WP Bakery Builder (backend and frontend editor) have disappeared from my options to edit posts. All thats left is the classical CSS code view. In addition, I cant access the screen options or help tabs. This seems to be confined to post editing as WP Bakery is available when adding new posts. It appears to be working fine with editing pages.

I have checked WP Bakery builder settings and the post box is ticked.

The only thing I have done recently is to move from http:// to https:// although I am not sure if this has anything to do with the issues above.

David

P.S. I am using Highen childs theme and my website is https://www.pulseandpea.com.