Homepod Siri used to say "Goodnight" when I said "Hey Siri Goodnight".

She used to say "Goodnight" then stopped - for no announced reason. With iOS 13.3 she came back to life, but with 13.3.1 she went silent again.

Is there a choice in this? - can I adjust a setting as to whether she speaks or not?

I happen to like her to confirm that she has understood my command. It's only polite to reply when someone says "Goodnight"!!!