What is the Stength of the character you are using? I know for some reason Larian added weight limits to armour so my Strength 8 character didn't pick up any as I went through the early game clicking Collect All on bodies. Patch 4 fixed you being able to move items in inventory that you couldn't move in the open world (you could get Lae'zel to pick up heavy items and then move them to anyone in the inventory screen).
I think 8 Strength can move items up to 15lbs, 10 Strength can move up to 20lbs, 12 Strength can move up to 25lbs etc. These weight limits seem to apply regardless of encumbrance which makes literally no sense; you can pick up 4 items that weight 15lbs each but the one that weighs 16lbs is a no-go...
I imagine it's coded that way because they didn't want elves with 8 Strength throwing barrels around the battlefield; but rather than code the "Throw" action to specifically recognize the limits, it was easier to just prevent all actions from working across the board and this odd behaviour is an unforseen contraindication.
