Left Rear Brakes Hanging at COTA

[Mike B CCTX]

I’m over my head with some brake issues I had 2 weekends ago with Chin at COTA. I had issues with lots of front end shake 2 weeks before with Edge Addicts at COTA. Had a cracked front right rotor. Replaced all 4 rotors with Stoptech slotted rotors and after talking to Mike Jr at Carbotech, went with XP20 front and XP12 rear pads. Saturday the brakes were amazing. There was lots of track dust because they were grinding the track smooth for the upcoming MotoGP event. On Sunday during the first session after warm up, still cool outside, it felt like my rear left brakes held as I backed off hard breaking at turn 15 and I spun. Went to hot pit and then back out on track. About the 100 meter marking I started hard breaking on the back straight. Again, Letting go with hard breaking, the front end went hard left and I ended up going backwards with brakes jammed full on down the straight and through the turn. I’m also running Castol SPF fluid and have the Z1 stainless steel lines. Running 18” square on Maxxis Victra RC-1. 275/35/18. Front camber of -3.6, front castor 7.0 and -0.01 toe in. Rear camber -2.9 and -.11 toe in. My Nissan mechanic inspected everything and can’t see any thing wrong. He did some 80-0 hard stops with no issues. Running HPDE3 with NASA in May, but no idea what to do with brakes. Looking for some input. Thanks