I'm having the same issue. Here is my summary:

1. App login results in ‘Invalid credentials’ error. Note that I’m certain I’m using the correct credentials as I can copy and past Username and Password from the app into a web browser and log in just fine. This tells me it’s not an account issue.
2. Uninstall/Reinstall of app and going directly to ‘Continue as Guest’ yields an inability to search for hotels. If I do ‘search nearby’, it finds my location, but says there are no nearby hotels (I live in the Milwaukee metro area with numerous properties within the search radius). If I enter any well-known location such as ‘Chicago’ or ‘Seattle’, I get ‘Sorry, we couldn’t find that destination’. This points to an issue with app functionality.

Note that the above errors track on two different Android phones (active OnePlus 8T w/SIM card -and- older Moto G6 w/no SIM used on WiFi only). This tells me it’s not specific to my the make/model of my primary phone.

I’ve spent hours on calls and chats with IHG, and while the seem to acknowledge awareness of an issue, no one will provide further details and the promised follow-ups haven’t materialized. I’m stuck with checking the app at random times and hoping I catch it at a time when it’s working.

Am I missing something obvious? Any recommendations on how to escalate within IHG?

Thanks,
Andy (IHG Platinum)