The inventory slots are bugged in the inventory. How do I fix that?

Ups forgot you have to turn the change slot arrangement setting to false to enable the advanced settings

Turn off the compatibility setting and set the positions of the slot by hand via config settings

Are you able to let me know what settings I need to put in because I have no clue lol.

you have to change backslot x and y to a position which fits your needs :)
You can play with it around but for full appliance you have to relog to your world

Ok. Would you have any suggestions for the back slot positions?

I just did -18 on both the x and y back slots and nothing happened.

It didn't do anything

Yes there is something not cleared out. You have to turn the compat setting to false for applying the advanced settings

Do you have anything to help with that?

So I turned the compat setting to false and I was able to move the back slots, but when I finished and exited out the world it messed up again and now I can't change the back slots.

Ok, that help and I was able to fix it. Thanks for the help:)