Deployment will only deploy your model to the cloud environment, not the database.
You’ll need to import the data on the cloud deployed version as well.
You could try to ‘add a snapshot of data’ from the modeler menu. This will commit a copy of your local database if its the default Mx HSQL database. The first time an environment runs, locally at least, the snapshot is used. I believe this also works for the sandbox environment. For more info als see https://forum.mendix.com/link/questions/15522