Exposing docker container ports not working

I am having trouble exposing a port from a docker container to my server. Here is what I've done:

I wrote a very simple spring boot app that runs on port 8080.
Now I am trying to deploy it into a docker container on my server. Based on the Spring - Getting started with Docker Userguide I've created the following Dockerfile:

FROM openjdk:8-jdk-alpine
VOLUME /tmp
ARG JAR_FILE
COPY ${JAR_FILE} app.jar
ENTRYPOINT ["java","-Djava.security.egd=file:/dev/./urandom","-jar","/app.jar"]

In a second step I copied my jar to the same directory (where the dockerfile is stored) and built the container with the following command:

docker build . -t testportmapping --build-arg JAR_FILE=swagger-v2-person-ws-0.0.1-SNAPSHOT.jar

Now when I run:

docker run -d testportmapping:latest -p 9065:8080

The command runs without an error. But if I take a look at: docker container ls: I see that no portmapping was created:

CONTAINER ID        IMAGE                    COMMAND                  CREATED               STATUS              PORTS                 NAMES
f15639c81903        testportmapping:latest   "java -Djava.securit…"   About 6 minutes ago   Up 6 minutes                              mystifying_payne

Does anyone know that I am doing wrong?

What I've tried so far:

1. Using different local port
2. Adding an EXPOSE to the Dockerfile
3. Addinng --net=host to the docker run command
4. Running the container attached to see if the app starts up correctly (it does)

My setup:

root@jupiter /h/n/d/p/swagger-v2# docker version
Client:
 Version:           18.06.1-ce
 API version:       1.38
 Go version:        go1.10.3
 Git commit:        e68fc7a
 Built:             Tue Aug 21 17:24:56 2018
 OS/Arch:           linux/amd64
 Experimental:      false

Server:
  Engine:
  Version:          18.06.1-ce
  API version:      1.38 (minimum version 1.12)
  Go version:       go1.10.3
  Git commit:       e68fc7a
  Built:            Tue Aug 21 17:23:21 2018
  OS/Arch:          linux/amd64
  Experimental:     false


root@jupiter /h/n/d/p/swagger-v2# lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 16.04.5 LTS
Release:        16.04
Codename:       xenial