Oil pressure will be higher when the oil is cold and at higher RPM, and lowest when it is hot and at idle. There are two engines manufacturer only gives min spec oil hot, 6psi at 1000 RPM, 18psi @2000 RPM, 24 psi @ 4000 RPM, same spec for both engines. I would verify oil pressure with a known good mechanical gauge.
Agree to use mechanical gauge to check oil pressure.Oil pump has a bypass valve to release excess pressure in engine.If bypass valve shot closed pressure builds up.Too high pressure could cause damage in engine . Even oil filter could blow up.They are not designed to hold that kind of pressure.