Devices keep playing and pausing music randomly, macOS & HomePod OS so far.

I really don't know which topic I should choose, so here I am.

I have a problem with something on my network keep sending out play and pause signal randomly. It will stick with one device, until I turned off that device, then the symptom would manifest in another device and that device would start doing it until I turn it off.

It started a few days ago with my Mac Mini M2 Pro, if I am watching a movie, the movie would pause and play randomly, obviously I can't watch a movie that way, so I quit VLC, then it will bring up Music.app and do the same thing. I thought it was the keyboard's media key, so I unplugged the dongle, but the Mac kept doing it. I finally turned off the Mac and see what will happen, as soon as I turned off the Mac, one of the HomePod started doing the same thing. If I turned off that HomePod, another HomePod would start doing the same thing...etc.

I've tried restarting every single networked devices, restarted all the routers... I've tried turning off individual devices and see whether it would stop, **** no... it's like the network is being haunted!

Any suggestions would be very much appreciated!