Same Plane, Same Airports, two days apart, different cargo capacities

In Domination VIII, my flight 93 operated by the same B737-900ER HGW, I see different capacities. I recently removed a long haul flight that was losing a lot of money and replaced it with shorter hauls, including a new flight between ATL and DEN and back again.

The new flights run every other day.
For 10 June, ATL to DEN, the flight shows 144 Y class seats, 20 C class seats, 4 F class seats, and 57 cargo available.
DEN TO ATL on that same day shows 144 Y class seats, 20 C class seats, and 4 F class seats.

The next time the flight is offered is on 12 June. Both flights show 144 Y class, 20 C class, and 4 F class seats. However, neither shows any cargo capacity. The flight immediately before the 12 June ATL to DEN is SJU to ATL. It shows 51 cargo available. The flight immediately after the 12 June return flight DEN to ATL is ATL to JFK. It shows 57 cargo available on the flight.

My FLIGHTS tab in Fleet Operations shows that 100% of the passenger seating is filled in all three classes for the 10 June flights but that is not the case for the 12 June flights. Details shown below. Highlighted area on front pic shows 10 June flights. Highlighted area on back pic shows 12 June flights.

Why do I have zero cargo capacity on those flights on those days?

Thanks.

Looking on the departure and arrival time of the 2nd flight, it seems that you are flying with a massive speed override. If you increase or lower the cruise speed it lowers the possible payload of the aircraft. If there is not enough payload available it first lowers the transported cargo.

If you go to your aircraft there is a link to the performance check tool. There you can check the impact of the cruise speed on the payload

Thanks. I finally got sufficient planes to set up a long-distance hub and ended up using this plane for a completely different route. Right now, the point is moot. However, I will try to swing back and check if I end up recreating the route with another plane.