Share your thoughts on DirectQuery for Power BI datasets and Azure Analysis Services (preview)

Thanks for the screenshot, Anonymous ! I confirmed with the team that this is by-design. Basically RELATED is not supported for weak/limited relationships, which includes cross-island relationships. This is the same behavior you would see if you were to have a composite model with two SQL DirectQuery sources (because they're in different islands), you can do this for import tables because they're all in the same (local) island.

You can find more info about this on the RELATED function docs here: RELATED function (DAX) - DAX | Microsoft Docs and the section on Limited relationships her: Model relationships in Power BI Desktop - Power BI | Microsoft Docs