Here are the collision settings for guns & magazines, hopefully this might fix the problem for you if these need changing:
How are you trying to implement locomotion? Could I see a screenshot of your blueprint graph? I haven’t looked at locomotion yet for this project, but it is something I will definitely be adding along with other features soon.
Teleportation should work on other levels, If you create a new level, then add a nav mesh to the ground & the Motion Controller Pawn - what result do you get when you try to teleport? Does it just show the teleportation stub or do you get nothing?