I do not remember how it works, but maybe Bitcoin Core is not synced, therefore newly created transactions were not transmitted. The question is at which stage of synchronisation it is. And will it publish transactions when become synchronised?
The transfer won't be submitted to the network until the local client is up to date. Up to this point, the transaction is shown in the local wallet but not in the global network / mempool. So yes it will transmit the transaction after becoming fully synchronized if all inputs needed for the transaction are unspent.