I'm assuming you checked the route map ( https://www.southwest.com/flight/routemap_dyn.html ) , as suggested on TA, which does show that there is a nonstop route from HOU to MBJ.

I flew on June 20, from CLT to MBJ and my connection was HOU. I want to say my departure time from HOU was something around 11:30am, nonstop.

I am also waiting for Southwest to come out with their next round of dates... I got my arrival flight and hotel for late April, but will actually have to go home, and JetBlue is still way to high!!!!!!