Field renames requires control over the consumer schema if you target to have a backward compatible deployment.

This means that you have to:

1. Register the schema version containing the alias to the schema registry (at this point both apps still use the old schema)
2. Deploy the consumer application to use the latest schema version (at this point, producer publishes with the old schema, but the consumer "understands" both field names)
3. Deploy the producer application to use the latest schema version (at this point, both applications communicate via the renamed field)

In this case, the deployment order is important and complies to being backward compatible. As you already saw, updating the producer first will break consumers due to the fact that they are not aware of an alias since they do not use that schema.