When the following conditions are met, a group conflict will trigger.

• The provisioned group name matches an existing group with the same name on the target Atlassian site.
• The existing group contains a different set of members compared to the members in the provisioned group. 

When a conflict occurs, the admins need to resolve them manually via the org administration (see document)

Suggestion : Allow an option to automatically override the groups in the Atlassian site with the provisioned group if there is a difference in group membership.