This is NOT resolved! This is a problem in 1.21.4. It creates a box completely filled with glass. NOT hollow
I am having the same issue on 1.20.6, running on Java 22. I have been stuck on "Saving World" for more than 30 minutes
Still a problem in 2024. 1.20.6 Not sure why this is NOT getting fixed
I tried doing it deep in the ocean to make an underwater glass home. Maybe it has something to do with the ocean/water?