Cannot connect to Power BI Service in Training Lab

[AJ_Walker]

I'm working thru the "Visualize Data in Power BI" lab, and first step is to connect to the Power BI Service.  From the Lab desktop, I open Edge, select the Power BI Service link on the Favorites bar, and click Sign-In.  But then I get an error 

"The connection for this site is not secure.  login.microsoftonline.com sent an invalid response."

Is there a way to get to the next step?  I've tried this on a couple of different days, but still same issue.

Thanks for any assistance.

[#2]

@AJ_Walker  Update, still in the training lab, I can get to actually sign in if I open a new private window in Edge.  But when I sign in, I get the error "Your connection isn't private" & "NET::ERR_CERT_AUTHORITY_INVALID".

Should I be signing in using a different user name, rather than my work ID?  I'm thinking it's trying to sign into my company's Power BI service, not the area for doing a training lab.