Although in general I disagree with those who suggest finding an ammo your gun "likes", because that's just too finicky for a defensive gun, I will cut a gun some slack if it doesn't like some really odd off-brand foreign ammo. Steel case Tulamo I would put in that category. Perfecta? It's supposed to be pretty good, but it's not something I'm familiar with.

I would send it back to S&W again. FTFeed issues are usually easy for them to solve. FTFire issues are more elusive.

This is not a peculiarity of small 380s; the LCP has a reputation for amazing reliability, and it's even smaller and lighter than the BG.

Let's see what is does with Win WB! That stuff was the nemesis of my 3 BGs, so I use it for torture testing now. If it will fire Win WB it will fire anything.

Good luck. If you like the gun, put the effort into getting it right with S&W, and it will be worth it.

David