When you change Market Centers, your team will need to be transferred to the new Market Center in order to keep the current team data. If a new team is created in the new Market Center accidentally instead of transferring, then it will be a completely fresh team account. If you encounter the issue that all the team data and contacts missing upon changing Market Centers, then this means a new team was created.
To resolve this, please reach out to your previous Market Center Administrator and ask them to transfer your team to the new Market Center. Also, ask your current MCA to deactivate the new team so that it is not visible and causing confusion. Once the previous MCA reactivates and transfers the team to the new Market Center and the new MCA accepts this transfer, you will see your old team data and contacts again in Command.