When a gun haven't a mag , it will cause the map display transparency.
When a gun have a mag , it will cause the map to full screen [have a chance happen , if it won't happen , it still display transparency].
These bugs will effect the map when a gun on player's main hand.

have no mag :
https://sm.ms/image/1odMsHrkOe38BWT

have a mag :
https://sm.ms/image/vdn2U9YxqZNR7A5

And when player discard a gun , will cause rendering bug.