Rgra66

I'm hoping that someone who has solved this problem can help me. I'm at wits end. I'm just a DIY'er that has average knowledge of engine repair and referencing GM service data. The truck is 2018 Silverado and has 130,000 miles on it. The misfire is only on cylinder no.2. The misfire only happens in park and at stop lights... any time the engine is at idle. When driving the misfire goes away, it's got power and no hesitation and no misfires anywhere. I run e85 through it all the time. I've done research and some parts canon things. I replaced both upstream O2 sensors. I replaced the ignition coil, spark plug and spark plug wire no change. I charged and load tested the battery all good. I did a compression test on cyl. 2 and came up with 208 psi. I took it to a repair garage for diagnosis, and they did all that I did and told me to replace the fuel injector and said while they were in there suggested changing all 6 injectors, so I did. No change still there. I replace the cam position sensor, still there. I replaced the crankshaft position sensor, still there. I have not pulled the valve to check for loose rockers only because I don't hear any tapping over that cylinder. I took it to a Chevy dealer, and they want to do high dollar thing to it, I thought they would give me an exact diagnosis but no. The code is a 300 not a 302 indicating cyl 2 specific problem. If cyl 2 is bad or failing why not the 302. I've had the truck since new always changing the oil religiously at 5k. The truck is babied no towing or pulling always on pavement and never beaten on or driven hard. I'm not opposed to digging into the camshaft or lifters, but my thinking is the 300, is something else messing up that is causing the random but specific misfire. Also I should note that there are no other engine codes to indicate another part of the engine leading to the p0300 it is the only code. Hoping someone has an answer.