Cwmbargoed Staffa and ticket

The line between Ystrad Myanch South Junction and Cwmbargoed is controlled by the staff and ticket system.
If two trains are to follow each other through the section it is important to only issue the ticket to the first train.
In order to enter the single line section the train staff MUST be present at the end the train is at.
It is not possible to move the train staff or ticket by road.
You will receive a penalty if you allow a train to occupy the single line without the staff or ticket.

Per the manual:

Quote:

The line between Ystrad Myanch South Junction and Cwmbargoed is controlled by the staff and ticket system.
If two trains are to follow each other through the section it is important to only issue the ticket to the first train.
In order to enter the single line section the train staff MUST be present at the end the train is at.
It is not possible to move the train staff or ticket by road.
You will receive a penalty if you allow a train to occupy the single line without the staff or ticket.

Click the buttons marked either 'Release Staff & Ticket' or 'Release Ticket' as appropriate before setting the route to Cwmbargoed. Check the timetable list (via F4) to see if the next working after 4C91 over the branch is from Cwmbargoed (in which case release both staff and ticket) or to Cwmbargoed (in which case release only the ticket).

I'm playing the Valleys sim for the first time and also had issues with the Cwmbargoed branch. I'm running the Cardiff Valleys SX 08 04 2015 0400 Start timetable and 6C91 refused to enter at Cwmbargoed, even though it gave me a delay notification of 23 minutes. About an hour later I noticed it still had not appeared as the staff and ticket were at Ystrad Mynach South Jct.

The only way I could think of solving the problem was to think of 6C91 failed and send a 0Z99 from Margam to Cwmbargoed to rescue 6C91 and get the token to that end of the line. It worked. As soon as my LE arrived 6C91 requested the route.