I got sram axs 12 speed on a new bike in January. The front brakes have always squeaked really loud: the bike shop has put new pads in twice and sanded the pads a couple times , cleaned the rotors and I think they sanded the rotors too but not 100% on that. I’ve broken them in each time they can’t figure it out. The rotor isn’t bent . Before I buy a new rotor and ideas ? The backs have always been fine and I’ve already replaced those pads once they broke in just fine: is there a brand of pad I might want to try ? Thx !