Mine did this a couple days ago.
I think I gave it a timeout for an hour or 2. but that was only so it didn't go flying out the window.
You can try rebooting your router/wifi.
HomePod seems really picky on wifi, and when it gets unhappy it seems to only fail certain tasks while others work fine. But the hoempod reset maybe should have fixed this?
just had a thought, You could also try triggering siri on all of your other devices (or rebooting them), it's possible one of them is stuck in the "I'm answering" mode. They have some sort of protocol so that only one device answers.
Maybe hompeod hears you, but your phone is saying "I got it" so HomePod goes back to sleep. I don't know if this is voice specific (might explain why your wife can use it) Triggering siri on the other devices might clear this.
For me, if I had to guess, I'd say it was my watch, siri has triggered on there a couple times that I didn't expect in recent software versions.