Really do think it's confirmation bias and not linked at all to his contract. Look at the fundamentals of our play. I'm not big on xG but... Auba doesn't contribute much at all in build up and so our drop off in xG is not due to him not playing well. We just aren't creating the chances for him to finish.
I'm not talking about Xg or any of that statistical nonsense. I'm talking about his actual contribution on the pitch. The man has limited skills sets but the few things that he is good at, he does them excellently.
However since the Contract renewal we have seen very little from him. Some of this is undoubtedly due to our general style of play this season and our overall ineffectiveness. That being said he's looked a shadow of himself.