Like the title says, Driving recently I got the dash beep and found out it has the dreaded low oil pressure issue. Car seems to run and drive fine except for the warning. Things done:

Changed to an OEM filter with Liqui moly 5w40 oil.
Replaced both pressure switches
Tested the pressure with a real gauge: fine when cold at idle (25psi), drops to (8psi) at idle when hot.
When hot, 42PSI at 3000rpms, builds quickly seems OK.
Engine seems to have no leaks.
The PCV valve is the newest revision, was replaced in 2015, no idea if it's OK or not.

I'm thinking of dropping the pan and replacing the pump. That may not be the right choice though. Since pressure builds well I'm guessing it's not the pickup. What is the smartest next step? Thanks!