Integration to PowerPoint via Publish to Web and Web Viewer Add-In

v-calis, 

I was able to get the web viewer Add-In and point to my power bi report, however, I'm experiencing an issue that I'm not really sure how to solve. After I enter my URL to the report and hit preview it shows that the page is rendered but it want's me to sign in. Clicking the sign in button doesn't do anything. 

Somehow yesterday I was able to get this to work. All I recall doing was using the URL from the IFrame embed code rather than the web embed url. Once I did this it started to render the report. However, today the report is showing the signin screen again. 

Now I don't mind that the report shows the signin by default, I assume it needs authentication for the current session. However, I can't figure out how to actually authenticate. I've tried logging out of Power BI in chrome and IE and then signing in again and then refreshing PowerPoint no luck. 

Did you experience anything like this previously? I know it's been a while but this is the only post I can find anywhere were the web viewer in powerpoint was even attempted. 

Thoughts?