Delete the custom.cfg files from both your Toribash installation folder (if there's one there) and from Saved Games/Toribash folder and try again - chances are there you got multiple instances of it which breaks how customs are being set.

To switch to old menu, do /opt newmenu 0
Keep in mind though, legacy UI isn't getting any updates since 2018 so you'll be missing on pretty much all the new features + any bugs related to it are not going to be fixed.