I had to test it a few times to figure out what was going on. Sure enough, it is like a sidestand interlock system on a motorcycle that will not let you start it unless you put the stand up or are in neutral... if the stand is down with the bike running in neutral, it kills it automatically if you put it in gear.
And to keep this post related to the original topic, I have to agree that after the first 300 miles or so is when I first noticed the problem with the 2nd gear to 3rd gear lag. It might be something that could be dangerous, but it is something that you can adapt understand. This issue is not there if you put your foot to the floor (in my experience). Rather it is during normal driving scenarios. I also do not believe it is limited to under 150 degrees. I was towing tonight and truck was definitely over 180 degrees and it did it with the tow/haul mode on. It will act differently if you are starting from a full stop. It acts differently when you turn from when you take off straight. It is very unnerving. However, when I put my foot down, the truck does respond. Is there a lag, yes, but that is to be expected in any case. What I do not understand is the text describing that all 17-18's are all this way. No they are not. I test drove several 2018's before buying my pre-owned 2015. Never did this dead-pedal feeling occur on those test drives and all of my test drives were from cold starts.