Oil temperature change over time

[JRS950]

Basics:
2018 3500 CTD 3.73 gears, 4x4, Aisin transmission now 41,000 miles. Bought 3/18

We tow a a 16,000 lb fifth wheel.

The first 18 months the oil temperature ran 201° under all conditions. Somewhere around the 18 month mark the oil temperature has now changed to 203° towing and not. I know that the oil temperature is a calculated number. I'm not worried about the temperature, just the change is what gives me concern. Anyone have a similar issue or any ideas?
Thanks for any information you may have.

 

[crash68]

It's a calculated value, whichever variables are used to predict the oil temperature may only have to change by a couple of tenths for the two degree rise you seeing.
Unless your having temperature issues, I wouldn't worry about it.

 

[OLEJOE]

My 18’ will run up to 195 and suddenly drop to 175 and start slowly going back up. I had the dealer look at it and they said it’s working fine. I just ignore it and motor on. It’s documented that I reported a problem.