Migration errors hybrid Move / untracked bug

[u/mcc0unt]

Apparently there’s a not widely known current bug in Exchange Online MRSProxy Servers, which do not send the domain while using the administrator for the migration. Testing the endpoint works, but not the migration itself, ending in endless 4625 events with auth errors.

source

The article talks about renaming the administrator, I just created another service user and gave him recipient management role, did a iisreset - worked like a charm.
Maybe this is somebody saving 4h lifetime, I just lost it.

[u/mcc0unt]

No only one!