How can I stop HomePod mini from playing music automatically?

I have just bought a homepod mini last week. However it is troubling me as it played music spontaneously and unexpected from time to time.

After adding the homgpod using default settings, on Monday, I was working remotely on my job when the homepod mini suddenly started playing music. I was not listening to any music or video, since I prefer silence when working on more challenging tasks. My husband was not at home either. Luckily I was not on an office metting. How embrassing it could be otherwise?

Then again on Wednesday, at about 5am in the monrning, the homepod started playing music at a loud volume by itself, again. Everyone was in a deep sleep. My husband was woken up and walked to the living room to turn it off.

We have no pets of any sort and no automation for playing music. My husband was irritated. He uninstalled the entire Apple Music and iTunes from his phone.

Does it mean the device is malfunctioning? Is there a way to disable music permanently?

[Re-Titled by Moderator]