The zone isn't working. They have people running free, giving too much space. They're not making contact as the ball arrives. They're not breaking on the ball, reading the QB. If they want to play zone they need to teach it better or get guys who already know how to play it. And they're doing neither.
This isn't to say they ran zone well under Golden. They didn't. But he was dumb enough to commit to it as a primary part of the defense.
If they go back to man, I'd expect an immediate reversal of this idiocy. A top 10 D.
You sure as heck don't run a scheme you don't know you're able to run against top 20 opponents. Mix it in, run it as you can. Don't just commit to it hell or high water.
A combination of a passive zone and passive pass rush is a recipe for disaster as we've seen.
Oh and play your best players. KVA and Tae Johnson need to start.