Steps to replicate the issue: Hold the the "Sickles" item (or any dual-weapon from the Dungeons Gear mod) in your main hand. The 2nd weapon is automatically equipped to your off-hand slot to mimic dual-weapons. When pressing [Q] to drop the item the 2nd weapon in the off-hand slot remains in your inventory. Moving the weapon from the off-hand slot to the hotbar duplicates it granting a new 2nd weapon to the off-hand slot in addition to the item dropped on the ground.
Steps to replicate the issue: Hold the the "Sickles" item (or any dual-weapon from the Dungeons Gear mod) in your main hand. The 2nd weapon is automatically equipped to your off-hand slot to mimic dual-weapons. When pressing [Q] to drop the item the 2nd weapon in the off-hand slot remains in your inventory. Moving the weapon from the off-hand slot to the hotbar duplicates it granting a new 2nd weapon to the off-hand slot in addition to the item dropped on the ground.
Mod version: [1.16.3+] Inventorio 1.6.1 Minecraft version: 1.16.5 Forge version: 36.2.39