New Bilton C.S issue

I've come across a issue that I don't understand why it's happening but basically 6R93 09:36 Willesden Euroterminal GBRf to New Bilton is signalled into New Bilton C.S as timetabled however once it passes the stop board for permission to enter said location, it than comes to a stop and reports that it's at buffer stop.

The next train to enter at that location is 4N81 which is the 18:51 New Bilton to Willesden Euroterminal GBRf but 6R93 doesn't step up to form 4N81 or exit the simulation at that location.

I click on 6R93 and tell it to run as 4N81 using the reverse train command, it does and it reports it's stopped at Signal RC4190 which is the starter signal for New Bilton C.S towards Rugby.

The next problem is the driver reports that they're waiting signal and want to depart but as it's the 18:15 departure and it's only 11:36, it's much too early to expect that the inbound train has been unloaded and is now ready to head towards London.

The save named Test is set at 11:36:56

Is there a reason for this behaviour?