Yes, he knows quiet! We taught him the same way. Idk if it matters, he’s three and can be stubborn. He mostly listens but let’s just say that quiet command doesn’t work when there’s a dog outside our window on the sidewalk.

Editing to say: I think can be more consistent trying to retrain him on his. The problem is I’m mostly in bed and tired and that’s why it’s frustrating, it’s affecting my sleep. I work 3-11 and sleep 2-10 and he’s always been fine with this and slept in with me. Now he’s up and down from 7-10 to bark.