Whole house filters are a joke.
I don't know why you have a pressure reducing valve on the suction line going into the pump (at least I think that's the suction). If anything it should be on the discharge side to adjust the operating pressure of the entire system once the booster pump is running.
Instead of a pressure switch to operate the booster pump, a flow switch would be a much better idea. When water flows, the pump runs and the reducing valve keeps the pressure at a set point. Flow stops, so does the booster pump.
Problem solved.