@Jrussi1301 wrote:
Case yes: Why Power BI Desktop RS doesn't it?
Because you cannot configure many to many using the RS version of Desktop this will mean this feature is not officially supported.
Case no: How is it running right now on my on-premise server? I did it using the normal version of the Power BI Desktop. And it is running clean, no fails. Can't find any difference between it and the same report running on the cloud service. And also in this case, is there a roadmap to it?
This happens from time to time. It could mean that MS have started work on supporting this feature. Or it could be a side effect of other updates to the tabular engine behind PBIRS. I have not seen any official announcements from MS on why they don't support m2m in PBIRS or whether it is on the roadmap for a future release.
But the fact that you cannot configure this in Power BI Desktop for Report Server means that if you have any issues (such as crashes or wrong numbers being calculated or if it stops working in future) - that if you ring Microsoft for support that they will not be able to help you. They will just tell you to stop using that configuration in your models and to only use the features available in Power BI Desktop for Report Server
