maybe you just never liked the dog and it picks up on that

Maybe it was one of his friends.

So he trusts those burglars more than he trusts you...

Dogs can read people. It’s probably not as “vicious” as you say it is and you’re just a jerk.

Dogs are highly intelligent creatures and pick up on people... maybe he just doesn’t like your vibe.

Sorry, the dog recognized the burglars.

There’s a reason for it.

Dogs that aren't specifically trained to be guard dogs or vicious towards strangers generally don't make good guard dogs.

That's a REALLY GOOD thing--your pupper is socialized properly! 'Guard dogs' are basically abused into it (police dogs are...not really treated great either, and have HORRIBLE relationships with humans other than their handlers, it's not good), and your pupper probably just thinks you smell funny. Try re-introducing yourself to the doggo with some treats and play. After a couple of times, doggy will start liking you more.