Oh yeah, I can see it now. Weird.
If I find any new ones, I'll post it in the steam discussions. For now, I'll just attach screenshots of the invisible walls I've found and see if you can find them.
Iron Isle:
Interestingly, I found another way to walk around it through the walls:
Lighthouse:
I couldn't find any ways to get to the entrance. If you'd like, I can send you one of my saves!
Edit: I will try again after I download the latest version!
Edit2: Tried the latest version and the lighthouse was fine. But the Iron Isle problems still stayed the same.