After i turn my car off, my fuel pressure drops to zero within 2 minutes. In the past my cars have held their fuel pressure for at least a day before they dropped at all. I'm not leaking fuel anywhere. It's an AEM fuel rail with an AEM FPR, and a B&M gauge. If air was getting in somewhere would fuel pressure drop. Actually, if air was getting in somewhere, i would assume the fuel would leak out.
Does anyone else have an issue with this, or is it just something that some cars do?

Also, when i turn the key to "on" the fuel pump cuts on and the gauge reads correctly, then just drops. The only way i can adjust fuel is with the car actually running. It only holds a number at that point.

Thanks