It is normal for oil pressure to vary up and down due to oil temperature and engine rpms. The oil pump is mechanically driven so oil pressure stays in step with engine rpms. Lower oil pressure at lower rpms, higher oil pressure at higher rpms. And cold engine oil is harder to pump than warm oil is so it is normal to have slightly higher oil pressure when the engine is cold.
The rule of thumb for acceptable oil pressure is approx. 10 psi per thousand engine rpms. That said, Jeeps newer than yours don't even show the true oil pressure any more. The normal ups and downs of oil pressure alarmed too many who were new to a true oil pressure gauge who complained to their dealerships. Jeep solved the problem of people unnecessarily complaining to their dealers about oil pressure variations by making the oil pressure gauge stay mid-scale except when something was really wrong with the oil pressure.