Can not invite from Homekit any more...

A few days back I was able to invite all iCloud users to "My home" on HomeKit (controlling IKEA Trådfri lamps). Now after I did a clean install of my Mac and iPhone this is not possible anymore, event though I'm connected via the Apple TV, and iPhone via my iCloud account.

On the invite page of HomeKit my family still appears but I get an error message saying they are not iCloud registered (when I know for a fact they are) when I select and try to invite.

I also try to invite entering the name/email manually; still same error. No one on the contact list are highlighted as iCloud users??

(The Apple TV in the living room is connected to HomeKit. The one on my bedroom is pending, never connecting.