Security roles not working properly after Fall 2021 update

v-chuncz-msft - I can raise this as a separate Issue if you would like but I suspect they might be linked. Let me know if you do.

We have a long-running active Power BI Embedded service with hundreds of users. This afternoon a user complained that they could see other users' data - that's never happened before. The PBIX file has not been updated, and an inspection of the website code has not revealed any changes (and no changes have been made today).

I have reinstalled a version of the PBIX from July and the problem persists, so I'm fairly certain it's not the recent update of the Desktop software. Evidence is starting to point to MS code running Embedded in the Service.

I can see from above that Microsoft are investigating. They are welcome to get in touch with me (if they read this), although to be honest I don't think we can tell them much as we haven't changed anything today. My colleague Tom is the best person to get in touch with via my email angus at oxfordpowerbi.co.uk. I can provide a mobile number for him. We are also raising an Azure support ticket this morning.

We have had to take down the service last night (about 10 hours ago). We will have to tell our users at 8am GMT (in 2 hours' time) that there is no service. This would be the first time since we began 3+ years ago. I am hoping that Microsoft are urgently looking into this.

BTW, i don't use calculated columns in the RLS model part of the PBIX.