I have a user that I migrated from on premise to Office 365. Before the migration the user only had one Contacts group. After the migration the user had two Contacts groups. I first need to know if anyone would know why I would have two groups after the migration. The second part of the question is how do I clean up so I only have one Contacts group safely preserving all the Contacts within one of the groups. This is a very critical user so I need to be 100% sure I have retained all Contacts before performing any deletions within this account.