Attempting to right click a shulker box already in an ender chest results in the item within the first slot of the shulker disappearing.

The issue only seems to occur when playing on a server with Charm and its option to drag and drop items into shulker boxes enabled.

The solution should probably be to disable this mod's shulker "bundling" feature when interacting with Charm and its own bundling feature.

Mods Used:
architectury-4.4.68.jar
charm-fabric-1.18.2-4.1.1.jar
cloth-api-3.2.64.jar
cloth-config-6.2.62-fabric.jar
fabric-api-0.53.4+1.18.2.jar
quickshulker-1.3.6-1.18.jar
RoughlyEnoughItems-8.2.470.jar

Thank you for letting me know it is Charm. You just saved me a couple hours of disabling mods, one by one. I just reverted 30 minutes of game play to an old save because I couldn't believe my eyes as my stacks of emerald blocks disappeared before my eyes in my survival world while testing a few different mod combos. You have 4 mods listed. I had 145. THANK YOU!

I simply accidentally right clicked my shulker box in my general inventory (not my hotbar) and an item seemed to be missing. I did it again. "wait, did that pull from the front? The mod docs said that some option would pull from last inserted and place it in an empty slot with R-click. R-click again. Oh, god!"

Disabling bundling has no effect.

Default Charm currently breaks any shulker box right clicks. Player beware.