When taking items from an inventory such as a gregtech crate occasionally the items will remain inside the crate's inventory despite them visually entering the player's inventory. The same happens when putting items into an inventory as well. It seems as though it happens when you hold shift + hold lmb and scroll over items to transfer them but go too fast and miss transferring one or multiple.

I'm hoping this can be fixed as it can be very annoying when inserting items into a machine and they just don't end up where you want them.

I experience this as well
I assume it's to do with mouse tweaks
might be worthwhile to check if this happens in other packs with that mod (e.g. GCP)

this is indeed a bug from mouse tweaks, this is a "known" bug kinda? it does this on other packs (GCP included). a few UI bugs are just caused by mouse tweaks which is unfortunate