I've found that the custom w_portalgun model has issues with collision when placed in the map (usually as weapon_portalgun).
Steps to reproduce: simply make a map and place the weapon_portalgun into it. Might be easier to see if the weapon_portalgun is in a confined area, such as an indent in a wall.
Steps to fix: remove all w_portalgun files from the vpk (v_portalgun is ok though).
I've found that the custom w_portalgun model has issues with collision when placed in the map (usually as weapon_portalgun).
Steps to reproduce: simply make a map and place the weapon_portalgun into it. Might be easier to see if the weapon_portalgun is in a confined area, such as an indent in a wall.
Steps to fix: remove all w_portalgun files from the vpk (v_portalgun is ok though).