Home app - not showing all members of home in each Home app

Hi

Will try and keep this brief!

4 members of family. I’ve just got new iPhone and old one passed to wife, who passed hers to eldest, who passed hers to youngest.

Home app was working really well pre-this change. Since making change (we did phone to phone transfers) my two kids weren’t in the home app under ‘People’. Tried to re-add and had multiple issues:

1) Shown as added on mine, but their screen shows new home completely empty.

2) Connects briefly, but on close and re-open then goes back to empty home

3) accepts but is then stuck on ‘Welcome to Home’ but ‘continue’ button doesn’t do anything and stuck on that screen.

I’ve ended up wiping my home completely, logging out of iCloud, TV, HomePods etc and running the HomeKit reset profile on all iPhones. Some progress seems to have been made in that I’ve got them all looking at the same home I’m looking at - now seriously depleted - but it’s still not right. Biggest thing is that on my iPhone is that all 4 of us are showing correctly. On the other three iPhones it shows me and whoever’s phone it is but ONLY those two people.

I have tried seemingly everything to get this rectified but I can’t do it. Can anyone offer any suggestions?

BTW, we’re all on our own Apple IDs running iOS18 on each iPhone. All TVs and HomePods are running latest OS too.

Thanks