Cannot provision Azure Sendgrid subscription

Question

Hello,

I'm trying to add SendGrid service to my Azure subscription, but I got following error when provisioning:

{  
    "status": "Failed",  
    "error": {  
        "code": "GatewayAuthenticationFailed",  
        "message": "Gateway authentication failed for 'https://rp.prod.marketplacesaas.azure.com/'. Diagnostic information: timestamp '20210826T155832Z', tracking id 'b1de8474-c6a9-46a7-bf5c-d926396f168e', request correlation id 'd4579a7f-aa6b-473d-9189-b9a101b97c10'."  
    }  
}  

I've tried multiple times with different resource groups at any time a day.

For testing, I've tried to provision the same on a new subscription and it worked well.

It's the first SendGrid account on this subscription, so I don't have any yet.