I noticed your question and I had the same problem. See above post. Bought the flow sensor kit online from Supply House. Note there is a very small nylon gasket that goes over the impeller which is easy to misplace or lose when you first disassemble the sensor. I believe this is important.
I have exactly the same issue. I am hopeful that this is the problem. Just ordered the flow sensor, if not, will likely just get a new pump.
Update: After replacing the flow sensor the pump stopped short cycling. The only other issue was that the pressure would get too low before the pump...