Overheating with clean rad and stock bike

Hi all my 2011 850 touring tends to overheat after a couple of hours of use.
The rad is spotless, coolant is topped up and I’m not running in low
I ride in Ontario Canada not the desert

I do have the Polaris cargo box on the front which clearly limits escaping air from the rad area

I would expect it to run cool all day long under normal conditions, is there a common issue or something I should check?

Thanks