As soon as one square is removed the GUI is closed and the leather is destroyed WHEN HOLDING A SINGLE LEATHER.

This is still an Issue even while running the newest version of the 1.18.2 ver2.2.26

hmm, can confirm.

So it seems to happen only in prod now, which explains why my last fix in theory, did fix it. It doesn't happen in dev because of an obfuscation issue.