2020 Paccar MX 13 smoking while idling

This is strange. I started the engine up recently, smoke was coming from the top of the engine then the engine shutdown.
I started it up a second time, same thing happened but it shutdown faster and I noticed that the engine was idlIng weaker than the first time.
I waited a while longer and started it up three more times everything was normal, no smoke, the problem corrected itself. I only show an amber warning engine light on the dash.
Any idea what is going on? The smoke was white I think but it is hard to determine because it is dark. I've been adding coolant to the reservoir periodically to top it off but not a whole lot.

 

Update the problem appears to be an EGR Bellows leaking on the upper right rear side of the engine.

 

Nope that light never came on. The issue never repeated and I've been driving the truck since just fine. No repairs were made the shop just identified the EGR Bellows leaking.