That can be normal after the car shuts off. But once the key is primed, the pressure should get back up to 30+ PSI and it should be 30+ PSI while cranking.
If you think it is the FPR, one can use a fuel crimp tool to CAREFULLY crimp the return line. If pressure goes up, that suggests the FPR is passing too much gas. If pressure does not go up, there is a pump issue. I will also note that a weak check-valve in the pump can cause pressure to bleed off quickly after you shut the car off.
Good luck.