You need to acknowledge the configuration on the TMS (Ctrl + 1) before the brakes will release. Check the manual page 20.
The picture of the video clip is misleading, watch it and you'll see that he's running TSC. Besides I'm not aware of an AP Class 350 for TSW!
I missed the AP bit as I saw a video that seemed to be for TSW6 But the Birmingham - Crewe does come with a 350 https://store.steampowered.com/app/...oast_Main_Line_Birmingham__Crewe_Route_AddOn/