I created my own account. Then, invited my wife. She received the email notification, installed (Mac & iOS(2)).
However, though her installation says "Jay's Vault" at the top, her installation does not see the Shared Vault I created. See two attached screen shots - one from my installation showing the sharing set on the vault, and one from her installation, showing the lack of shared vault.
What did we do wrong?
1Password Version: 7.3
Extension Version: Not Provided
OS Version: macOS 10.14.5
Sync Type: 1Password