Trying to equip new gear straight from the chest section of the inventory is broken. The following bugs happened to me in the bone keep.
Dragging gear from the chest will cause you to instead drag an item from your inventory. This happened to me after fighting the Female Vampire, and I tried to collect the Shield and Plate Mail. Possibly relevant, my inventory contained enough items for me to have to scroll to see them all.
Additionally, in the previous room or so where there is a Magnificent Dagger, I opened the chest with my Paladin, then tried to drag the dagger over my rogue's character icon on the left side to try and immediately give it to him (again, from the chest). This caused the Dagger to completely disappear, both from the original chest (or drawer) and all my inventories. It was also not on the ground.
Best,
Havck
I had the same issue. The game always takes the items from the characters inventory, if there are any "behind" the chest slots.