I have 82 devices in HomeKit, including six HomePods and an AppleTV 4k as home hubs. I wouldn't say everything works perfectly. Most things work pretty well, but I have occasional automation failures, occasional disconnection of devices, and so on. All the usual drama. Yesterday I decided to take another photo on a long-term problem ... I use two eero Pro 5 routers that are enabled in HomeKit, but in the last few months Homekit Accessory Security has been disabled because that button was in gray. I had tried everything by bike (I was really "lucky" when a power outage forced a power cycle all over my house) and none of it helped. Anyway, yesterday I decided to disconnect from iCloud on my iPhone and connect again. Voila. Homekit Accessory Security was no longer gray, so I turned it on and checked the boxes for Chamberlain, Lutron, Signify and Starling. I left Belkin because the imposition of historical security on Belkin gave me trouble. Maybe I'll try again later. However, there was a negative side effect when disconnecting and connecting to iCloud, which may also be evidence of a positive effect. About eight of my devices lost their camera affiliation and entered the Default Camera by default. I should have paid more attention, but I think most, if not all, of them were Lutron dimmers that were otherwise completely bulletproof. I reassigned the cameras in a few minutes and checked if the scenes, automations and shortcuts that refer to these devices were ok. Yes, they all looked ok. Another side effect was that I lost all my camera and home wallpapers. Since the photos were saved in a single shared album in iCloud, it was only a matter of minutes for me to fix them. A little preparation goes a long way. It's only been 24 hours, but since you disconnected from iCloud and logged in again, everything else seems to be working better. And keep in mind that I only disconnected from the iPhone. I didn't disconnect from my laptop or many other iOS devices, because my iPhone is my main interface to HomeKit and also because disconnecting from a single device solved the problem I was attacking. The bottom line, yes, was a bit of a pain, but I have to guess that the loss of some of my "data" also suggests the loss of some spider webs. In my case, the cost was worth the benefit.