Portless with ssh port forwarding: 400 Bad Request The plain HTTP request was sent to HTTPS port

In my use case, I use ssh port forwarding to connect to some parts of our infrastructure and portless could be a nice way to organise all the localhost connections.

I'm running into https issues, though. I have a fast api app running on a remove server made available under localhost:9206 using ssh. I'm using the proxy like this portless proxy start --https and then:

❯ portless list

Active routes:

  https://myapp.localhost:1355  ->  localhost:9206  (alias)

Trying to open the API docs page in the browser leads to:

400 Bad Request
The plain HTTP request was sent to HTTPS port