Solved

Issues loading iGP and/or images?

If you are having trouble loading the app or seeing something like this, we are currently experiencing issues with our CDN (Content Delivery Network). The situation is the responsibility of Microsoft, and is not within our control.

Among with tens of thousands of servers from Amazon, Microsoft etc. the CDN was blocked in Russia by the government just 1-2 days ago which resulted in exactly the same symptoms. Naturally, my initial speculation was that these events may be related, but it appears to be maintenance (reasons for maintenance are unclear). Monitor the status / situation here:
https://azure.microsoft.com/en-us/status/

Regarding the situation in Russia, you can follow that on a separate thread:
https://igpmanager.com/forum-thread/12928

For any aspiring game developers among you, or those interested in what it's like dealing with these situations:
https://twitter.com/jackbasford/status/986360887580811264