From Matt Coller's site:
With cornerbacks out, it was clear from the Bears’ lack of eight-man boxes (22% vs. Dalvin Cook’s season average of 30%) that Chicago wanted to keep everything in front of them. While Kirk Cousins did hit on some explosive passes, his targets downfield any farther than 10 yards were limited. NFL NextGEN stats show in his passing chart below that he only threw the ball just eight times more than 10 yards in the air.
After the game, Cousins explained.
“We did call a lot of plays trying to take a shot and it just didn’t time up with the defense they were in,” he said. “They were playing a deep shell and trying to keep everything in front of them and that’s when I’d have to progress and check it down. A couple other times they had a good rush and they did get in and it forced me to kind of have to progress more quickly. It’s kind of a combination of factors there.”