App platform docker failing SSL with custom domain

Hi,

I’ve done the following:

• Created a custom docker container containing a django webapp fronted by gunicorn.
• Created a container registry in digital ocean and uploaded the image there.
• Created an app platform using that docker image.
• Checked that this image runs using the inbuilt domain. Everything works and the app runs! However, I’ve now bought a domain from an external domain provider. I’ve added that to my app platform using the “We manage your domain” option and the networking tab tells me (after a bit of a wait) that digital ocean is happy it now can serve the domain.

However, my app platform no longer works. Clicking on the old URL gives me a 400 bad gateway and clicking on the new domain gives me an SSL error (SSL_ERROR_INTERNAL_ERROR_ALERT on firefox). Are there other steps I need to take (e.g. in the spec file) to link up the SSL config for my custom domain?

Thanks