Did this start after the oil was changed? Have you checked to make sure the oil level is correct and not overfilled?
What you described sounds like the valve seals are failing and allowing oil to drain past them and down the valve stem. When you first start the engine, the oil gets into the combustion chamber, and you see smoke for a short time.
I attached a pic below showing the seal I'm referring to.
Let me know.
Thursday, September 15th, 2022 AT 9:03 PM