Cannot authorize Enphase

I cannot seem to get the v4 autoupload to work with my new Enphase system. For the Enlighten-ID (which is not exactly in the URL like in the manual) I filled in the location ID in settings. The API-key (user id) I also found under account and access control.
However, when I click “Authorize” it says “Failed to authorize PVOutput to read your Enphase site data System not found”
What am I doing wrong?

Changing the system without an auto-uploader, saving it and then configuring the auto uploader again somehow worked!