0. ALWAYS PROVIDE INFORMATION ABOUT MODLOADER (Fabric / Forge) AND MOD VERSION (For Example 1.19.2-8.2.10)
   CurseForge Mod Loader and Launcher
   Mincraft Version NeoForge 1.21.10 - 49 BETA
   Server and Client are on latest NeoForge Version
   Back Pack mod is on latest version
   MouseTweaks and MoremouseTweaks are on latest version
   For more inforamtion about mods, you can write me anytime!

1. Describe the bug
   When you have your Backpack on (any Tier Level) and you have activated the first slot blue (Select Mode) you cannot Left-Click with Shift to any Items, which are not already in the backpack and can stack to them.
   You can set other slots to SELECT Mode but the first Slot has to be unselected (not blue).

2. Write steps to reproduce the bug
   Go to backpack, go in options, Enter select mode and "blue" the first slot (top left)
   Now click SHIFT and click on the items in your inventory (cobble stone for example).
   The items should move to backpack but do not. Unselect the first slot and try again --> works

3. What is expected behaviour
   Even top left slot is selected (blue) items should move to the back pack

4. Screenshots (If applicable)

If first Slot is blue, moving is not working

Thank you for your great work and this wonderfull Mod!

It will be fixed in the next update