My HomePod mini is not working

Keep your HomePod up to date, because I’ve read that several HomePod updates contain improvements. If it is, contact Apple for help. Only if it’s dead and not fixable by anyone you can throw it away and buy a new HomePod.

I am also experiencing issues with HomePod mini and Gen 2. Since 17.6 I've found they become hubs more frequently then before the update. As a result my automation has become very unstable when they are in the hub role.

I've since learned through trial and error, observing their behavior in the Home app, they are VERY sensitive to power fluctuations or low voltage. If they share a crowded power strip with other power hungry devices, consider moving them to their own outlet.

I've since tuned my setup to address voltage issues and find the HomePods have stopped disconnecting, they are more stable, but they continue to fail running home automation and home shortcuts. Neither the mini's or the HomePod 1st or 2nd gen can run them without issue.

I've read that using an 128gb ethernet Apple TV as a wired "headless" hub improves the situation.

Good Luck. And Provide Apple Feedback through their Feedback Assistant. It ensures your issue is classified and routed to the correct team. Link to your threads on the subject and make it clear the scale of the issue by including "Me Too" or "Like" counts in your ticket.

if it was me then I would read

Someone has found a way to fix software bricked HomePods (9to5mac.com)