Well, I couldn't do it before now but I finally got it fixed for the backpack puzzle as well as the larger door puzzle. Fixed a bug as well.
Hope you don't have any trouble playing it now!
I played through again. It turns out the items will rotate/shrink (sometimes) if I click on the very edge/outline of the item. I use GDevelop myself (found this game through their YouTube channel sharing it on their community page) and the only reason I can think of that I am having trouble when others are not is that maybe the "held" condition is set to the mouse being on the item while left click is being pressed. I'm using a touchpad and while it usually works fine for me, maybe something about the way this item is set up finds whether or not I am clicking to be uncertain. I replayed the backpack one more time and the items sometimes rotated when clicking the middle if I was very careful to have my finger on the bottom left corner of my pad (left click), but it was still very finicky.
Anyway, want to say I enjoyed this adventure and am glad to have reached the end. Maybe the bunny will go on another adventure with his new friend :)