Hello. Came across this tread searching on this topic.
I use HomeBridge and a awesome plugin called "Homebridge UniFi Protect" that allows me to integrate my Ubiquiti Unifi cameras into HomeKit.
Since it set this up a couple years ago, i am running into this very annoying issue of my HomePod Mini (HPM) speaker always taking over as Home Hub over my wired and much better Apple TV 4K 2022.
When the HPM is the main hub, the cam feeds are slow to load and motion clips sent to HKSV often fail as the speaker's cpu is not nearly as powerful as the ATV or the wifi is slower etc.
The issues immediately go away when I unplug the HPM.
Apple
still, does not have any setting to disable their smart speakers from being a Home Hub.
Very aggravating.
I tried setting the HPM on its own isolated wifi network, but then it fails to trigger most commands, and says that line that make sure you iphone is on the same wifi network as this device...