On your iPhones/iPads, try turning the default "Private Wi-Fi Address" feature OFF for your Home[Pod] WiFi SSID(s). The feature as implemented can confuse peer-to-peer connections on many home networks (particularly mesh setups).
Settings --> Wi-Fi --> [Your Home(Pod) Network] > (i) > "Private Wi-Fi Address" = OFF.
NOTE: This will cause a "Privacy warning". You can ignore this. There's no risk; it's your network.
Next, reboot everything (including WiFi infrastructure) and reset your homepods so that they learn you've set Private Wi-Fi Address OFF for the network. This guy reports observing MAC address changes on his HomePod mini until he turned off Private WiFi Addresses and reset his homepod: https://www.reddit.com/r/HomeKit/comments/rxkcqh/homepod_mini_private_address/. HomePods shouldn't use private wifi addrs, but they do get the network details from your iphone.
Background: Starting with iOS 14 (late 2020), Apple made iOS devices use a unique random MAC address by default on every WiFi network you connect to. They did this to prevent nefarious snoopers from tracking your iPhone hardware's WiFi MAC address across WiFi networks. I've never heard of any such snoopers or any exploits/hacks associated with WiFi MAC address tracking (although I've searched for examples). Seems like Apple's best example of a solution looking for a problem.
Please report back if this advice helps bring stability to your Home[Pods]. Or not. Thx.