Why you think the number of baggage carts is a "difference from the previous version" ? As explained in the manual, since the first version, the number of carts changes depending on your airplane load so, if it's not always the same, it's because your airplane is not always loaded in the same way.
In any case, I cannot reproduce the problem. Boarding completes normally here, and I can then request any other service, like Pushback.
It's possible you changed the boarding times in the Timings section of the GSX Settings ?