There appears to be some more stuff involved there as the inner text box is much smaller than your outer one. I’m not sure how to achieve that.
If you’d like you can send a small example file with this one stack in there and I’ll be able to fix the bug straight away. Looks like an easy one to squash.
If you sign on to the slack group slack.yourhead.com you can send large files just by dragging a zip file into a private message. But whatever way works best for you – a Dropbox share to our customer support email is also a good way.
Thanks for the bug report,