Hey everyone! This was a pretty hard thing to debug since we had a hard time getting things in a reproducible state. The latest Beta build of Local was just released and has a fix that should get this working:
Since the beta version and the stable version of Local are two separate apps, you can install the beta version alongside the existing stable version. You’ll want to only run one version of the app at a time, since they both try to make use of some common resources.
Can you download that latest version and see if it allows you to create new sites that can be reached over HTTPS?
Note that if you are using the beta version, this won’t fix the certs for existing sites, you’ll need to delete those certificates first and then re-trust them.
Thanks for your help in finding and zeroing in on what was going on, and let us know if you have any other questions!