My Ford truck has an oil pressure gauge, and it holds pretty steady. It does tend to drift up and down +/- 10 psi or so over long periods of time, based on the engine oil temperature I think. But it doesn’t jitter. What I’d do is take it to a shop and ask them to use their shop oil pressure gauge to see if they notice anything like that with a calibrated known to be working gauge. If it doesn’t do that on the shop gauge, you know the problem is with the sensor, gauge, or other electronics between the two. Another idea, a faulty voltage regulator can cause this, either in the alternator, or the one that regulates the voltage to the dashboard electronics. My guess, most likely just the sensor or its connector.