I have one client site using The7 theme at WPBakery Page builder.
The only issue I came across was with the major 5.0 update. The builder could open up into the modules, but the modules were blank, or if there was text already in the text module, then it wasn't populating.
Once I upgraded then it worked.
And now that I think about it...it "may" have been the other way around where after I made the update, it wasn't working, and had to roll back temporarily.
Other than that - I love the theme and the builder. :)