I recently had someone resurface my pool. During the resurfacing, they noted that the skimmer was not holding pressure per their test (long story short, these guys weren't 100% reliable and wanted a 3rd party's opinion).
After filling up the pool, the old pool pump (discontinued model) wouldn't prime. I installed a Hayward Super Pump and attached CPVC/PVC valves around it. Initially, it was observed that the PSI gauge would shoot and float to around 30 PSI and there were some bubbles coming out of the jets. The skimmer seemed to have an extremely small amount of suction alongside the pool jets to the point where it was unnoticeable to most. Water was still flowing through the pump though.
I've already run an in-scent test around the outer piping to identify if any air was being leaked into the pool without anything being obvious. I also shut off multiple paths via the diverters to see if anything caused the pressure to stabilize. Sometimes there were minor 5 PSI fluctuations. For the most part, the PSI remained at 25-30.
My biggest fear is that I have an underground piping leak causing air to get into the system. My theory is there's a leak between the pool suction and the pool pump.
Any guidance to an assisted answer or anything I can try would be helpful. I did already try to blow out the lines with a shop vacuum to check if there was any debris blocking the water flow. It seems that the air went through the pipes just find and shot the water up wherever appropriate.