Adam,

 

1) When I paste directly to the main area of the groupbox, I still get the same issue with the editor clearing up and freezing.

 

2) When I paste into the title area of the group box, it works fine and doesn't append 'temp_span' but appends 'v' instead.

 

3) After pasting into the title area and then pasting into the main area of the group box, the text is pasted but it moves up to the title area with 'temp span' appended to the content.