Scabbard Sword interacts quite weirdly with Backslot whilst it's installed, if possible, can you have NEA auto-disable Scabbord Sword when Backslot is installed?
Seen in issue report here:
Globox1997/BackSlot#51

Thanks! It mostly effects multiplayer as it's quite inconvenent to remind players to disable it in config, since it appears to be a clientside option

Yea I can look into that later, for now just disable the Scabbard feature in the settings/config.