Webhook with basic auth works on HTTP but not HTTPS

I have a server running which is protected with basic auth. The server has an endpoint that I want to reach with a POST request. When testing the endpoint using software like Postman or Restler (Android) I can see that I’m getting the correct response using both HTTPS and HTTP.

However, when running a Webhook integration on the Particle Console it only works with HTTP and not HTTPS. I’m getting timeout errors when running the request throught HTTPS.

I’d rather not keeo the HTTP site running at all due to security reasons so any help in getting the Particle Webhook integration working on HTTPS would be greatly apprechiated!