External Account not restored

we have migrated an account from one Zimbra server to another using zxbackup but the external gmail account which was configured in the source server did not get restored. The folder where the external emails are delivered to was created okay. At this point I attempted to re-create the account in preferences but it would not allow me and said it already existed. Dropping to the CLI and executing zmprov gds account@domain.com yielded that indeed the data source was present. Had to delete using zmprov dds account@domain.com datasourcename.

Is this a known issue or should a bug be raised ?