we have developed a custom solution using that we are creating a modern team site in sharepoint online,which works well.
but for one site we are having issue that, when we creating this site, we are giving the title as xxx , this name associated group is created but site was not created, as the group already exists it is not allowing to create the modern team site with same name.
So we have deleted that XXX assoicated O365 group and tried to create the modern team site and provided the title as XXX again, in this case site was created but it title created as XXX65, url is like https://yyy.sharepoint.com/teams/XXX65. but Associated group was created as XXX only.
is there any specific reason that it adds 65 at the post of the title for site??
When you delete the group, have you checked whether the associated site collection has been created? Maybe you can manually create this site collection with the name you wanted to use from SharePoint online to see if it allows you to create that. If it doesn't that means the site collection with the same name/URL exists already.
With the new version of SharePoint admin Center, you would be able to see all types of site collections including the ones that are created with group creation.