In Urho3D game engine for physics simulation used physics engine Bullet Physics Library. All deal in him. Triangle mesh from Bullet can be only static, it won’t work properly on dynamics objects, i.e. if ther mass is other than zero. Use convex hull instead. You must use trianglemesh only for static objects, because it meant for only objects that don’t move.
Bullet expects triangle meshes to remain stationary. You could combine several convex hulls/shapes instead, if you really need extra detail.
Do you try to use your ‘highdetail’ mesh as input? That may be the cause for being ‘offballanced’. You can use a simplified mesh for collision on an animated model. For this you need to create a special, more simple mesh for being used as convex collision model and the one you already have will only be used for rendering.