Might it be that your old Planet API key expired already, i.e. due to Planet subscription expiring?
We have initiated a new onboarding to the Planet’s portal and you should have received a message from them, which you should follow up on.
Did you not receive the message?
@gmilcinski We haven’t received any message yet. I am not sure where exactly to expect this message or in which mail.
Since this is a bit urgent, I am moving this conversation to support@sentinel-hub.com