HomePod (both styles) can't find anything in the Apple Music Library

First, I would like to say that if you intend to post a link about "setting up the HomePod" to answer my question, let me pre-flame you by saying stop worrying about your stats and wasting my time with your response. Read the whole post, OK?

Second, I've have HomePods for about 3 years and never had this problem. It's happening on all of my HomePods (currently on HomePod Software Version 16.1) except for one. Which is super-weird.

Third, I can access all other features on all of the HomePods. This is not unique to paired (stereo) or unpaired units. Nor is it unique to mini or full-sized HomePods. Nor is it unique to where it is in the house.

e.g. "Hey Siri, what's the weather today?" It responds with the accurate weather.

e.g. "Hey Siri, turn off the lights." It turns off the lights.

e.g. "Hey Siri, Red Alert." Runs my pre-programmed Scene named Red Alert.

e.g. "Hey Siri, play music by ____________."

"Got it."

"Working on it........"

"I can't find any music by _____________ on your Apple Music Library."

Not only do I have plenty of songs/albums by _______ Library, I pay for the Apple Music Service.

Here's what I've tried: rebooting, unplugging for 30 seconds and plugging back in, clenching my fist so I don't throw the speaker on the floor to see if that helps.

That's about all the detail I can think of.

Thoughts?