You are NOT alone, and this is well documented on this and other forums. BAD levers just flat fuck don't work with certain rifles. Case closed.
Mine caused a fail to lock back about 25% of the time. It is not mag related as the same mag will work fine once, then fail to lock back the next time. I've switched buffer weights, tried several different types of magazines with the same inconsistent results. I realized I was spending a lot of time/money on trying to get a $30 add-on to work like it should. I trashed it, and my carbine works perfectly again. I WISH the BAD had worked, but I don't NEED it.
BTW, my rifle is a high quality build (LMT complete lower, BCM Middy upper with BCM BCG) so I'm having difficulty blaming the problem on my weapon that functioned correctly before adding the BAD.
That being said, I DO think the BAD is a sweet idea, but IMHO it's something one needs to experiment with before affixing it to a defensive firearm.