Since update to 1.7.1, the builder interface has started jumping around a lot when the mouse cursor crosses the boundaries of elements. It might have to do with the new element labels attached to the boxes, but that’s just a guess. Video above shows the bug.
I realized why this issue occurs. It’s actually just with elements that are at the end of a page. e.g. when there’s nothing else following the last section, then hovering over the section, everything jumps up because the section label pops up below the section. I guess perhaps adding a bit of default padding to the bottom of the builder or the last element in it might fix this?
I was going to reply to you yesterday, but the video wasn’t ready to be watched then I was able to reproduce the issue and added it to our bug tracker.