Shooter bug and other related RayCast issues such as C-Foam going through doors and Mines not killing players are caused by a Unity bug detailed here: https://issuetracker.unity3d.com/issues/raycasts-fail-to-hit-collider-when-there-is-a-different-gameobject-with-a-collider-very-far-away-in-the-scene
This bug happens as a result of projectiles with colliders falling out of bounds and travelling super far away as a result causing the above Unity bug to occure.
Any object with a collider that can travel out of bounds can cause this bug, but the worst offender are gun magazines as these persist through level restarts, and thus continue to fall even during lobby screen.
Since this bug can happen due to ANY object with a collider travelling far, its hard to pin-point it to a single object. (A player throwing a glowstick down elevator hole can induce the bug if the level is played long enough). As a result a simple fix such as disabling gun magazines isn't as viable.
For this reason, this plugin prior-level start will check ALL objects with a collider and destroy any too far from world origin. During gameplay, it checks every 1 hour (configurable). To prevent hiccups during combat it will only perform the cull while you are out of combat.
This plugin only culls objects for the local player, this means that if someone else has become shooter-bugged this plugin will not save them unless they have it installed as well. As a result, if host gets shooter bugged and as a result C-foam stops colliding with doors (I believe this is host-side calculated) then there is nothing you can do. In general it is best for either everyone to have this mod installed, or restart the game / switch loading between expeditions.