Hi @Jennifer_Parmeley,
Could you please click Switch account on the visual and log in with your Enterprise account on your page 3? And then tab back to your original report page. Then you should be able to sign out your ArcGIS Online account and switch to Enterprise on your original report page.
Also, I noticed that you were using old version of Power BI Desktop from your screenshot. Please make sure to update to the latest version of Power BI. You will see something like this when you switch account after upgrading.
Please let me know if you have more questions!
Thank you!