Non Mopar oil pressure oddity

If you really had 0 oil pressure, the engine would not likely have survived the 1st session like this without serious damage. (A full synthetic might allow it to survive for a few minutes, but the key word there is MIGHT.) So, it is very likely the sender or the gauge itself sticking.

The big lesson to learn from this is if you see 0 oil pressure STOP the engine NOW. It is very unwise to not fix the pressure indicator right now; buy an after market gauge and sender right now and slap it in.