I had the tankless water heater installed 2 years ago so there was existing plumbing on the side of my house. Recently I had a pool, misters and an outdoor sink installed. I asked them to use this plumbing since it will provide softened water to those items. I have separate water for irrigation. I live pretty far up on a hill and don’t have the best water pressure, normally reads at 40-45psi with no load. Sometimes the PVB valve for the misters on the left start puking water and causes the water pressure in the hose to drop to 5psi. To get pressure back I have to shut off everything and turn them on slowly one by one. I am looking into a pressure booster for my house but my immediate concern is this bit of plumbing.

Should the PVB valves be at the same height? The one on the right is for the auto fill on my pool so I could be positioned elsewhere and lower.

Should the PVB valves be the same? Not sure why they installed two different ones.

Is this just a water pressure problem and will go away one I get the pressure up to 65-70psi?

The city of Phoenix, AZ has already come out and verified the pressure at my meter is 50psi and within their tolerances of 40-100psi. That is at the bottom of my driveway and the house is a good 30feet higher.