Failed Migration, and now cannot get user moved

Hi

I have an Exchange 2007 SP3 environment. I installed Exchange 2013 as the Hybrid server, so I could migrate users to O365.

I tested with 4 test users, and the migration went off fine.

I tried with another user, and the mailbox move failed. The users was still able to access their on prem mailbox.

Now, when I logon to the Office 365 portal, and attempt to move that user again, It shows that it starts syncing, then it zero's out the syncing tab (in the status dashboard) and instraucts me to finish the migration batch. All this happens within a minute.

Is there something that I am missing so I can re-attempt to move that user?