Do I need to be whitelisted?

I’m trying to deploy Sketchup for Schools as part of our 2020 SOE. I’ve added it to our O365 business store, but logging in we get “This app requires an internet connection and looks like we are having trouble connecting right now”, directly after the “Redirecting to your organizations sign-on portal” step.

The machine I’ve been testing on has no firewall restrictions, so I’m pretty sure it’s not that. I’m not sure if we need to be whitelisted - if so, our domain(s) are, and

Can someone provide some advice?

@joy should be able to help