Control Joint Availability of Two Servers

Hi,

I want to model what is exactly described in the link below, which is:

"Suppose that each entity undergoes two processes, one at a time, and that the first process does not start if the second process is still in progress for the previous entity. If you connect a queue, a server, and another server in series, then the first server can start serving a new entity while the second server is still serving the previous entity. This does not accomplish the stated goal. The model needs a gate to prevent the first server from accepting an entity too soon, that is, while the second server still holds the previous entity."

http://au.mathworks.com/help/simevents/ug/keeping-a-gate-open-over-a-time-interval.html#bqajiaa

I tried to implement it but it doesn't work! This is my model (base on the example in the link):

the unloading has a service time of 2 and Manouvre has a service time of 5. So the entities should leave the queue at time 0,7,14 and so on. but the results are as follow:

which shows that the first entity enters the first server without waiting for the second server to finish with the previous entity.

Is there anything that I am missing in my model?