Sometimes, depending on the configuration in Administration > Modules > Group > Data privacy, users need to confirm a group invitation before becoming a full group member. This confirmation is usually done right after the next login.
Very often, users receive a mail notifying them about the invitation to the group (screen mail). If this group is used in a course, it contains a link to the course. If a user now clicks on this link in order to go to the course, he will log into OpenOLAT an go straight to the course, skipping the group invitation confirmation step.
If the user logs in without following the provided link, he can confirm the group membership, if not, he will not be able to confirm the membership.
The membership confirmation should always be displayed, not matter how the user logs into OpenOLAT.