Microsoft 365 Apps Admin Center - Inventory Error

We're running into issues trying to access Inventory in the 365 Apps Admin Center (https://config.office.com/). When trying to swap a specific group of devices to a different update channel (Current to Monthly Enterprise), we go into the Apps Admin Center, select inventory and receive a generic error:

There was a problem showing the security update status information. Please refresh the page or try again later. 00000000-0000-0000-0000-000000000000

This has been happening for 3 days now. Was working fine prior to that (and were able to flip a few devices earlier in the week). Anyone else experiencing the same/similar issues? Multiple 365 Admin's within our organization are getting the same error, so it's not isolated to 1 person/1 account.