Military adviser not reporting on some civs

[WiccanFerret]

What causes the military adviser to give no input on some enemy civs from time to time?

 

[HammerandSickle]

What ticks me off is that the only civ that I want displayed is not...

 

[WiccanFerret]

Yep. And I've tried making sure there's a military unit of my own either in their territory or on their border...