She looks more like a mountain cur than a BMC?
Anyway, yeah...curs tend to act like elitist assholes. Some might compare their attitude as more feline, than canine! If you don't have their respect, then you simply do not exist. And if you don't have anything they want, you don't exist, either. And if you are outside of their 'circle of trust', then you are similarly ignored. Given that, a cur dog damn sure ain't gonna obey someone who doesn't exist, LOL!!!
That said, cur dogs certainly are trainable! My cur is over 7yrs old now, we are bonded at the hip and he minds me well. Just giving you hope that you can 'fix' your pup! The strange thing is, contrary to their perceived 'hard headed' working nature, curs can be VERY sensitive to correction! Be very, very, very careful with corrections. Make absolutely sure your timing is perfect, and the level of correction is only as much as needed. This is true for training any breed, but cur dogs simply do not respond well to harsh correction, and can actually be broken (in a bad way)...
As a comparison, ol' timers would whip their hounds with a switch to correct them, and the hound would be none the worse for wear. But if you take that same physical approach with a cur, you'll be 'blacklisted'...that cur will NEVER trust you, again! Curs are not 'one track minded' like a block headed hound, they learn....and learn, FAST! You can even see that in how curs hunt. Unlike hounds who trail scent from footprint to footprint, good curs tend to 'think on their feet' and will figure out how to 'cheat' a track. Just sayin', you're not dealing with a dumb dog! Curs are problem solvers, so that can present a challenge when training them. That doesn't make training more difficult, it just behooves one to know the animal they are dealing with, so as to implement a training regiment tailored to their individual personality...
Please be mindful that if you go overboard and take your frustrations out during corrections, you can literally RUIN your cur pup. With that in mind, an e-collar is a 'life saver' as a training aid, as it removes YOU from the correction. But please educate yourself on when/how to use an e-collar, or find a good trainer who knows the nature of cur dogs! In that regard, keep talking to as many cur owners/breeders as possible. Confident you'll hear a similar opinion, and hopefully you'll find a trainer that can help...
I'm not a trainer either, but have a pretty good handle on my cur. He's a handful, but ya wouldn't think so if you met him. Feel free to PM, happy to share my experiences!
Beautiful dog, wishing you all the best!