Similar issues happening for me:

• My partner isn't showing on my household account, but his Aviois balance is.
• Tried to add my brother to the household account; it sent the invite but he never receieved it. I clicked "re-send invitation" and it deleted the invite, so now errors out when I try to re-invite!
• Called BA and they said they couldn't access my account, and to call back in a few days if problem still persisted.
• Checked on my Family & Friends account - it's empty and asking me to set one up. I should have 5 members in there!

Of course, none of my trips are showing up on the website (they're on the app though).

Will call again today as I need to borrow Avios to secure some flights by end of next week.

IMO this new website user experience is really poor, and it akes FOREVER to load up, if it ever does get there.