L5P bottom engine tick

[Rme2513]

Truck started ticking after the first oil change so I took it back to the dealer and they looked it up and found a bulletin on it. Does anyone else’s have this “ normal “ condition or know anything about what it actually is ? Is there another type of oil that makes it go away and why only the first 20% of the oil life? Witch I have not reached yet but curious why it did not do it when I first bought the truck it now has 5500 miles on it 

 

The noise i hear is what they define as the Diesel engine tick