This is a common issue that occurs with group members invited to take the IBI. They receive an email invitation asking them to take the IBI, but when they log in to the site, they don't see the group invitation waiting for them.
This usually occurs because the email address that the invitation was sent to is not the same as the email address the participant used to register for the IBI. The email address used for the invitation and the one used to create the account must match.
To solve this issue, ask your group member which email address they used to register. You can then resend the group invitation to the new address.
Once the invitation and the account match, the group member will see your invitation and can join the group. If they continue to have trouble, contact our team at email@example.com.