From the posts it seems majority if not all of problem homes have HomePods (and minis). Has anyone using Apple TVs only for hub had problems with 16.2 update? I have Apple TVs only and made sure -all- devices in the family (many) were updated before Home upgrade, and it went smooth, and works better than before.
Also consider, if you have Wi-Fi only home devices (no Bluetooth), there is no to little value to having multiple home hubs (redundancy sounds great, but there seem to be bugs with switching hubs currently). If you have a stable Apple TV / HomePod (ideally one with wired network connection to your home router), enable HomeKit on that device alone, and -disable- HomeKit on the others (no standby, disabled). With standby, through the course of software updates, power cycles, and Wi-Fi network loss (which happens more frequently than you see, it could be sometimes firmware upgrades in the middle of the night), the active hub changes to a standby one (you've probably observed a different Apple TV/HomePod becoming active from time to time), and I think this brings up unwanted dynamics and bugs, at least prior to 16.2 (before 16.2 I had problems until I disabled all but one Apple TV for HomeKit).