Strongly suspect that the inventory/weight changes in 2.0 bugged out this sidequest. For reference, my playthrough started pre-2.0 and I have been continuing it since the patch. This might not apply to playthroughs started post-patch.

After you view the braindance and get taken to the scav hideout, your inventory gets stolen from you and placed into a locker. Holding F to "take all" out of the locker places everything back in your inventory but the weight is completely bugged. I started with around 100 weight in my inventory and upon recovering my items this went up to 600, making me overencumbered. Saving after recovering my inventory and then re-loading from that save caused the inventory to re-calculate to the correct post-patch values.