Shared home invitation does not work

I have created a new thread for this issue as at least three years since HomeKit users began reporting this issue, Apple appears to have done nothing about it. I have three accessories set up via Home for iOS, and they all work as expected on the devices which are all signed in with my Apple ID (An iPhone XR, a 1st gen. iPad Air and the new iPad). I would like to be able to invite my wife to use those accessories, (being able to turn lights on and off is a pretty basic requirement for a home you live in), but right now this is not possible. Having already tried to send her an invitation to share my home which resulted in her receiving the invitation but it then 'hanging' once it was accepted, this also forced me to delete my home setting and then needing to reset all the accessories and adding them again to my home setting.

I do not want to have to go through that process again until Apple can provide some assurance that this long running issue has been fixed, or another Communities user can suggest a workaround.

My wife only has one device to which she is signed in to iCloud, a first gen. iPhone SE (running iOS 14.3)

I have a 4th gen. Apple TV, fully updated as my Hub, and my iPhone and both iPads are also running the latest possible versions of iOS and iPadOS. All those devices are signed in to our respective iCloud accounts, both of our accounts end with @icloud.com

Apple, what are YOU going to do about this? Thousands of people have bought in to the HomeKit ecosystem, and they are unable to allow other people in their homes to control connected devices using their own Apple devices.