I found it has conflicts with this addon.

https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=2871172464

this addon appears to conflict with the following addon:

https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=2156004721

when both addons are enabled, gmod base weapons and workshop sweps are still automatically picked up when player walks over, yet entities such as ammo and health vials are not auto-pickuped.

Not sure if anyone brought it up yet, but whenever you drop a weapon with (example pistol slot) left open to take after while standing on top of the pick up range before maxing out the inventory. The slot acts as if the dropped weapon was never dropped due to the new weapon thats part of the category trying to take place, but unable to be swapped to until any other weapon was dropped. (take your time to respond if you come back to view mod)