Steam Class 66 Airedale & Wharfdale - Train Puts Emergency Brake On?!

I have been having a problem with the class 66 recently on this new route where I am going up to full speed (60mph) and I am always less than 10 miles away from the destination then suddenly the brakes go on with no DSD or AWS warning.
Its quite frustrating and I have tried to reset the locomotive but when I set the cab back up again the brakes wont release and the throttle does not work!

Can anyone assist me in this issue and/or let me know if you are experiencing a similar issue!

FYI - I play on PC - Steam