When I use the dynamic brake on the SD70 on Sherman Hill it automatically cuts out when I apply either the auto brake or independent brake and can’t re-apply until auto brake and independent brake is released. This is on Xbox Series X
I believe that's intentional. You would need to bail off the independent brake for dynamic brakes on the loco(s) to be effective.
It doesn’t happen though on all the other American locos. On SPG I use the auto brake with dynamic brake coming down the grade to control the speed. On the hill start tutorial the the SD70 I used the auto brake with the dynamic brake no problem.
Doesn‘t change the fact that it‘s prototypical and very much intended. Which is correct if you bail off the loco brakes. Even with no interlock, you never use air brakes and dynamic brakes on the same wheels at the same time since it reduces the effectiveness of braking.
That’s the thing, I never bail off the brakes in the loco when using the other locos such as AC4400 on SPG. I will do another run with The SD70 and try using the dynamic brake with the brakes bailed off in the loco and see if that works but I didn’t have to bail off the brakes in the SD70 Hill Start training module.