Guest access to Project Online without incognito mode / separate profile

I'm having problems with guest access in Project Online, following these instructions:

Let guests see your project in Project for the web (microsoft.com)

I can only get this to work based on the following steps:

1. Use incognito mode or create a separate browser profile
2. Goto project.microsoft.com/THEHOSTDOMAIN.COM
3. Login with the external guest account

When you do this, I noticed that I couldn't see any projects when the project page first loaded, but after refreshing the page they appeared.

Is there a better way?