Here another example from demo. In Safari double click on the word "about":

Another screen record here.

I've got digging into the sources and found a place where prosemirror calculates coordinations
https://github.com/ProseMirror/prosemirror-view/blob/master/src/domcoords.js#L237

I have supplied a PR to prosemirror-view as their example also suffers from wrong positioning.
So if they merge it should fix our menububble too.

The PR won't get merged unless these two issues (ProseMirror/prosemirror#900 ProseMirror/prosemirror#899) are solved in Prosemirror.

So the only option would to implement the changed cordsAtPos function into the menuBubble itself.

center on selection start?

i can do this 10 ways from tuesday whats prefered?