Sessions doesn't communicate with Mueller...Sessions stated early on that he would avoid news reports, official memos and any information about those things Mueller is investigating...Kinda like the 3 monkeys covering their eyes, ears and mouth...
I seem to recall Sessions saying that about all the matters that he is recused from. He doesn't pay attention to the details, because he's recused.
When Sessions received the Nunes memo, I wonder if he even read it before he passed it on to the IG (and to this other person that he won't name).
How else would one explain Sessions keeping Rosenstein in charge, whilst the Nunes memo shows that Rosenstein signed off on a bogus FISA application?