During testing I tried reauthenticating the connection for the action multiple times with different accounts and in different flows, I tried from different machines using different browsers, I tried recreating the entire flow and still encountered this issue when it was happening. If this was a simple authentication issue then any one of these should've resolved the issue. It was not.
Fortunately this issue hasn't occurred this month and most of the last, so I can ony assume changes were made to the service, as nothing has changed in the flows or the accounts I'm using. It's frustrating when MS can't keep services stable enough to use. The fact they don't even acknowledge many of these issues is even more infuriating.
