Dank Null Version: DankNull-1.12.2-1.7.97 (and .98)
p455w0rds Lib Version: p455w0rdslib-1.12.2-2.3.161
Forge Version: forge-14.23.5.2847

Steps To Reproduce:
Only happens with newly crafted empty dank/null
1.Right-click with dank/null on the docking station
2.Shift-Right click with dank/null on the docking station
3.A duplicate of the dank/null shows up in the offhand slot

Was this tested on Single Player or Server (or Both)?
Singleplayer
Was this tested with just Dank Null installed?
Yes