ahhh, well that’s the first thing to work-on, then. Possibly broken AmmoJS plugin. hmm. Wingy tests.
Meantime, maybe we both need to read… https://forum.babylonjs.com/t/ammo-js-collision-response-and-filtering/
Advanced AmmoJS collision crap… with forum friend @MackeyK24 . I’m far from AmmoJS expert… barely introductory levels. Let’s also beg for help from @Cedric, @RaananW, @Raggar, @trevordev and whomever else we can bother about Ammo. 
Not many web-docs about Ammo. Sort of need-to use Bullet docs.