WTF is my fuel pressure doing??

[stroke of luck]

I have an Isspro EV2 FP gauge. Just bought a couple of months ago. As you can see, it's pretty much going crazy. I've checked my grounds, they're all good. I've tested all the voltages and everything is within spec but when I'm testing it, the gauge is always holding steady at 58 psi. Once I start moving, it starts acting up. At first, I thought the pump was losing prime but it still does it with a full tank. Just changed filters too. You think bad gauge sensor or pump motor issues? EDIT** it's plumbed into a FASS 150

[no-tel-in]

when you nail it, what does it drop to?

[stroke of luck]

well if it's not jumping around, then it only drops 1 or 2 psi. I forgot to mention that the sensor is plumbed into my FASS 150.