I am adding users to a Site in SharePoint by getting the Microsoft-365-Group behind the Site and adding the users as members of that Microsoft-365-Group. I use the method described here. However, it can take a long time until the user that was added can access the SharePoint Site.
When I create a Microsoft-365-Group using the method described here the users can access the SharePoint Site that gets created for the group immediately.
I can't find any documentation that explains or even mentions this delay except from here. Does anyone know why this delay is so long when everything else within SharePoint and Graph API seems to be within a minute to propagate? Does someone know of an alternative method to add users to a Microsoft-365-Group using the Graph API that does not take so long time?