"SSL Certificate Not Provisioning for Custom Landing Page Domain — 'SSL Already Issued' Warning"

Hi Marketo Community 👋

I'm running into an issue with SSL certificate provisioning for a custom landing page domain in Marketo Engage and would love some guidance from anyone who has experienced something similar.

*Setup:*
• We recently changed our primary landing page domain to a new custom subdomain
• The CNAME is correctly configured and fully propagated globally, pointing to our Marketo instance 
• Our Marketo instance is on Adobe Experience Cloud

*The Issue:*
The SSL certificate is not provisioning for the new domain. In Marketo Admin > Landing Pages, the SSL Certificate field is showing as `-`.

When we tried to set up the domain, we received a warning saying *"SSL certificate has already been issued"* — suggesting a pre-existing SSL certificate exists on Marketo's servers for this domain but isn't being connected automatically.

*What We've Already Tried:*
• Checked the "Generate SSL Certificate" checkbox when saving domain settings — SSL still shows as `-`
• Used the "Add SSL" option in Admin > Landing Pages > Rules tab — button was not functional
• Tried emailing support@marketo.com — received auto-reply that this is no longer active

*Additional Context:*
• We're also unable to revert back to the previous default domain
• Landing pages are currently serving over HTTP only
• We're in the process of getting Marketo Support Portal access to open a formal case

*Questions:*
1. Has anyone encountered the "SSL certificate has already been issued" warning before? How did you resolve it?
2. Is there any self-serve way to connect a pre-existing SSL certificate to a domain in Marketo?
3. Any tips on expediting a Marketo Support case for SSL provisioning?

Any help or guidance would be hugely appreciated! 🙏

Thanks in advance!