Sorry if I missed it, but are you taking the oil life monitor right down to 0% or close to it? What miles does that come out to?
I also have a 2019 classic I bought used as an ex-rental in July 2020 with 15K miles on it. I've been using Supertech, Napa or Havoline full synthetic in 5w30 flavor along with $2 Champ filters and changing it at a ~5K miles interval. I've also been using a bottle of Lubegard biotech or a bottle of MoS2 in with the fresh oil here/there. Not every OCI. The additives were an impulse buy early on. Once they're gone, I'm done with them.
Currently 55K miles on it. Used oil drains out dark @ 5K miles with my almost entirely highway usage. (I average 20-23mpg tank to tank hand calc).
I can sporadically get it to tick for 2-3sec on startup under only one circumstance. Start the truck to move it and quickly shut it down. We're talking 10-30sec of run time. On the next restart, it may or may not tick for 2-3sec.