HomeKit "Home hub not connected" - why?

I have been using HomeKit for months now with no issues. I have four Apple TVs (and now a HomePod) serving as 'hubs'. I have multiple scheduled automation tasks that worked fine.

Recently, however, the automation tasks are not running, and underneath each automation task I see the message 'Home Hub Not Connected'.

When I look at the list of hubs (under Home settings), all 5 of them are listed in Standby.

I've tried rebooting and upgrading all ATVs to latest release but still no luck.

Anyone else have this issue?

 

*bump* this is still happening to me constantly. Has *anyone* else had this problem? I turned off beta updates for my ATVs and iOS devices, so they're all running the latest released version of iOS/tvOS.

 

Update - logging out and back in to iCloud on the Apple TVs seems to fix the problem. For a while, one of the ATVs shows 'Connected'. But after a couple of hours all the hubs are in 'Standby', and none of the automation works. So frustrating.

 

UPDATE: I think I fixed it (in case anyone else has this problem).

I set the 'Sleep After' to 'Never' on one of my Apple TVs. I then logged out and back into iCloud from that ATV. It has shown 'Connected' ever since. I suppose I could disable sleep on the others but it probably doesn't matter at this point.

This is still obviously a bug, because even when all the ATVs go to sleep it doesn't 'promote' the HomePod to be the active hub.