I think a little more information might be needed. Are you saying that Fermentrack is calling for cooling when you don't believe it is needed, or the refrigerator kicks on even though Fermentrack is not calling for cooling?
I would recommend that you let the BrewPi PID algorithm do it's thing. It's usually proactive to avoid over/under shoots.
Also, what is your Beer probe placement like? Inadequate isolation from the chamber air will cause some oscillation of target chamber temperature. The fact that you are switching between heating and cooling makes me think you might not have an ideal probe placement.