I am trying to sign in using a different account to the Power BI windows 10 app. I sign out of one account and then try to sign in to the other using the "use a different account" option and I just get signed in as the same account again. Nothing comes up to allow me to enter new credentials.
Are using Windows Phone or a desktop/tablet device?
If you are using Windows Phone, you need to make sure that the account you want to use for authenticating agaist Power BI is configured as work or school account in the device setting.
I am using Windows 10 on a desktop. I have two work accounts. Up until this week I have been able to use either account, actually the other one is the main one I use. I am guessing something changed with the app that all of a sudden it doesn't allow me to switch.
The Windows 10 Settings app lets you create a new account for a friend or family member, as described in the previous section. And it lets you tweak your own account, changing your account password or switching between a Microsoft or a Local account.