When you make a DMView in the Portal, and you don't receive any data, this is the solution to fix it:
When you create the connection to the DMView Database within ETL+ you can select Direct connection. Turn direct connection off to fix this problem.
See picture below.
You can find this at:
1. Open ETL+
2. Go to tools and select settings.
3. Then select the connector that connect to the DMView Database.
4. Turn Direct connection off and click on OK. Now the settings are saved.