Password App not sharing passwords with invited family members

So I have a family set up and I am wanting to share passwords with one family member through the process in the new Apple Passwords app. All looks perfectly fine, however, the invite sent to the intended person never arrives and they therefore don't have access to the group and passwords I created for us. There is no email invite, phone message invite, anything in their apple account, nothing.

Yes, the contact details in my contacts is 100% correct. How do I rectify this to give them access to over 100 passwords?

Thank you in advance.