I'm not sure why, but sometime recently shift drag functionality is no longer working for me. Are there general reasons you've found for this in the past, or possible incompatibilities that cause this? Any help would be much appreciated. <3

(I am running on Fabric loader)

Doesn't sound like something I've encountered before. Maybe it's some other mod causing issues, try with just Mouse Tweaks and nothing else installed.

I'm not exactly sure which it was that was causing it. But I deleted Easy Shulker Boxes and Create mod (Fabric Port), and also went back an update for Forge Config API and it seems to be a non issue now. If I had to assume, it was Forge Config API. Sorry for the possible confusion. Love the mod, thanks so much!