I opened a ticket with Apple Developer Support and recevied an email back with the assigned ticket number.
But I'm not sure what happens next? Does someone contact me by email? Is there an SLA by which time they would contact me?
Thanks
What is the process for Apple Developer Technical Support really contacting you after you open a request
Best I can offer is a link to the support page detailing the process:
https://developer.apple.com/support/technical/
It doesn't commit to a SLA response target as such, but it does offer the following:
Your incident will be assigned to a Developer Technical Support engineer who can help troubleshoot your code or provide workarounds to fast-track your development. Responses are delivered via email in English, typically within three business days.
-Max
What happens next is for you to wait to be contacted by email. As noted, it can take a few days. At least this is how it has worked for me on more than one occasion in the past.
Use the time to ready a sample project that demonstrates the issue for handoff.