Question about Oil Change Interval warning...

[Cj60]

I purchased my 2015 Ram 1500 a couple months ago with 56k miles on it, and had the oil changed soon after. I reset the Oil Change Interval notification. The sticker they put on my windshield and it said I would need to change oil again after 6k miles. The other day, the warning light came on saying I was in need of an oil change and it has only been 1857 miles since I had it done.
Could it be because I just had the PCM reflash due to the recall, or is something else going on? Being my 1st Diesel, and it being so dang expensive, I cannot afford to be changing the oil that often but don't want more things going wrong with the motor.

 

[CAVEMANN]

Mine did nearly the same thing, bought it Dec 30, a 2017 Big Horn ECO DIESEL with 14343 miles, after just about 1900 miles the warning came on.
"OIL CHANGE REQUIRED" I had enough oil on hand but no filter, so I reset the the warning and ordered a filter. I did the oil change as soon as the filter came in. Why did it do it?? I have no idea, but figure it either wasn't changed before I bought it OR the oil life monitor didn't get reset, either way, I am certain it has the right oil and a true indicator of when to change it. It's got just over 5000 miles on this go round, haven't decided if I'll do 6k, 8k or follow the monitor, it will depend some on how things go after I do the tune, it will be here Monday, I would like to get the EGR COOLER recall done first, and then will tune it & change the oil. I'm currently a touch over 22000 miles now. I strongly advise a gauge package that will show DPF soot mass and REGEN status, I have a SCANGAUGE X that is setup & programmed with those PID's, and more that I programmed, I think I put in everything I could find for it in addition to the default ones. I replaced it with a new EDGE INSIGHT CTS 3 for the extra functionality.