Steam Spg Csx Sd-40 Stealth Gray (from New Journeys) - Can't Get Brake To Release

I got the CSX stealth gray SD-40 New Journeys add on for Sand Patch Grade and can't get the brakes to release. I ensure the auto brake is set to Freight, the MU-2A valve is set to Lead, and I release the auto brake and the independent brake. However, it still shows that ~20 psi of air is still in the brake pipe. I check the immediate trailing unit and see it's MU-2A is set to Trail 26, the auto brake is cut out and the handle is off, and the independent brake is released.

What am I missing?

 

Did you follow the tutorial for any of the trains for that route? If not, I suggest doing that.