I edited your post to add code blocks. Please, format your posts according to the following guide: How to format your forum posts
In short: please, use </> button to share codes, terminal outputs, error messages or anything that can contain special characters which would be interpreted by the MarkDown filter. Use the preview feature to make sure your text is formatted as you would expect it and check your post after you have sent it so you can still fix it.
Regarding the issue, are you sure it is actually listening inside the container? What is the http error code when you try to access the port? It is possible that port works perfectly but there is something wrong with the app itself and doesn’t give you a response.