When I try to list channel messages I get:
[...] "code": "UnknownError", "message": "Failed to execute backend request." [...]
This error is for all teams I don't belong to.
I have this error when trying to call the API from Microsoft Flow (with HTTP GET) but also with Graph Explorer: the account I used has FULL permission but still asks to check my permission:
Failure - Status Code 403, 656ms Looks like you may not have the permissions for this call. Please modify your permissions
And the registered application has the delegated permission needed to call this endpoint regarding the documentation:
GET /teams/{id}/channels/{id}/messages
https://docs.microsoft.com/en-us/graph/api/channel-list-messages?view=graph-rest-beta
Is it a bug because of the "beta" or something I've missed?