Yep the bug mentioned is a bit of a bane of my existence, I fixed a lot today ... but not that particular issue. Easy fix is to have it rotate 90 degrees instead of 45 but i felt this takes away from the Rotatron aspect :(.
For learnings sake the main issue is the collision box.... learning for puzzle games make them about 50% smaller. I think this would fix it a for the most part, I also made it so pieces held don't interrupt place pieces as I found this problematic too.
Thanks so much for taking the time to play and give feedback :)