Originally Posted by Peckish

There are some corrections for that pattern, I'm not sure if your tree is part of them? Scroll to the bottom of this page.
https://www.fiberworks-heine.com/faqs.htm

If that doesn't address it, I would try one of two things. 1) Make the block out of scrap fabric and see if it fits, or 2) email the designer.

Good luck!