local Ember-cli server with Wit.ai

I'm having an issue using wit.ai from a local ember-cli server.

Wit uses web sockets to connect to a service that returns speech to text with parsed entities, intents, etc: wit.ai example docs.

For some reason I can't seem to figure out, I cannot connect to wit from any page being served by ember-cli. There are no errors thrown, the service says it's connecting but never returns the connection. For reference, the same code connects 1) fine from a page served from a simple python server (see the example linked above), and 2) when the same ember codebase is served from an aws EC2 instance.

To remove complications I've already set connect-src: "*" in the content security policy, and on wit.ai's console I've allowed connections from all, but neither of these things have helped.

Anyone know what I'm missing?