Well after a good run of no issues there for a while, we have a problem. Maybe a really big one. Not even sure where to start with this one. Car seems to be running okay still. Smokes really bad at startup, then goes away after about 20 seconds. If the car sits off for very long (15-20 minutes) it smokes again on startup
Seems like you are burning either coolant or oil, with the latter being more probable cause in my opinion. I’d try pulling spark plugs for starters to see how they look.
I would say cooked valve joints that let the oil falling in the cylinders when the engine is stopped.
Engine out job, of course…