GUI Slots Issue (past 27)

So I'm making an item based GUI inventory that acts like a chest. I've done it before up to 27 slots (technically 28). However, when I try and go above 27 my game crashes. I'm wondering if there is a way or if it is possible in the first place for me to have a bound inventory above 27 slots. I would presume it is considering double chests exist but I'm not too familiar with how to do it.

I've tried different ways of doing it and even applied my own code to it but I still can't get it to work. Either I'm doing something wrong or MCreator has a hard cap limit on GUI slots at 27.

Any help would be greatly appreciated.

Thank you,
- Shad