High oil pressure at startup

[dingo7285]

2018 ram 1500 3.6

So about a month ago had oil filter housing replaced. Mechnic was a bit rushed to finish. A few weeks ago i started noticing a hestistion at startup. Then got a bit worse, and threw code for misfire on 2. As i started paying more attention, noticed that at startup oil pressure is high 65-80 on dash, and blowing more white exhaust then normal.
Once warmed up, oil pressure drops down to normal and no white exhaust.
What coild be wrong? could the oil filter houseing replacement be realted? Should i stop driving it until i bring it in (to same mechinic)?

 

[El Huapo]

If your oil pump on the 2018 is like mine on a 2019, the oil pump is a dual-stage model and yes, high pressure upon startup would be normal. My truck often sits for long periods of time so I like the high pressure, thinking it lifts the crank right away, limiting wear and tear.
The white smoke is a different puzzle though, sounds like maybe coolant leak into a cylinder?
Old School: black smoke is fuel, blue smoke is oil, white smoke is coolant (getting into the cylinder(s), coming out the exhaust). Now with new tech and synthetic oils, that old school stuff may not be useful... Can you borrow a coolant tester from a parts store and look at your coolant chemistry?