I have a 6 port low-profile in floor cleaning system. I have noticed that as it cycles through the zones one zone always has the heads popped up. The other Zones will come on and off as they should but seem to be low in pressure. The Zone that stays up happens to be the one that has two ports in the system going to it...meaning in one complete cycle it will pop up twice. I have checked everything and even replaced the 2" t-valve all six ports. Just not understanding why that one zone always has increased water pressure to it.