Vacuum Pump Switches Direction During Seeding

My students and I have recently started creating seeding sequences using FarmBot. We encountered an odd behavior in the middle of our first trial run. We successfully sowed two seeds in the appropriate locations, but upon the third return to the seed tray during the sequence, the vacuum pump started blowing air outward instead of drawing it inward. It has been blowing air out ever since, even when initiating the pump from the peripherals on the control panel. I’ve tried to reboot the FarmBot hoping it would reset, but no luck. Can someone please let me know why the pump would suddenly switch its direction and what the fix would be?