Unintended behaviour setup:

ModList:
-Harmony
-Core
-Armor Racks
-Pick up and haul

Dev-Quicktest for a random start.
I've built a steel armor rack, set the inventory to flack armor, unforbid the armor pieces, ordered a pawn to haul the armor.

Unintended behaviour: Pawn will pick up the item, they will drop the item on top of the rack (like it's a shelf), and pick it back up, dropping it near the armor rack, and attempting to pick it up and place it again on the armor rack. This behaviour continues untill a work more important is aviable. It very often makes pawn stuck.

I've also tried with swapped mod orders (Armor Racks <-> PUAH), with no change in behaviour.
Mod settings makes no difference either.

I've the Dev of Armor Racks said that it has to be fixed from PUAH side since my mod uses the base game's storage mechanics.