Traefik 500 Error on one container port, but not the other

Hi all,
I am using Traefik as a reverse proxy for accessing a container image which itself has an http interface on port 8080 and an https interface on port 8443, which I need to reach. Using my current setup, I am receiving a 500 error via Traefik when setting the loadbalancer to port 8443, but everything works fine if I set the port to 8080, with the exception that I do not want to reach that port. This is the beginning of the error in debug mode, I can provide more if needed. The log of the docker container is empty.

'500 Internal Server Error' caused by: net/http: HTTP/1.x transport connection broken: malformed HTTP response \"\\x15\\x03\\x03\\x00\\x02\\x02P\"

My compose.yml:

version: "3.7"

services:
  traefik:
    image: traefik:2.6
    container_name: traefik
    restart: always
    ports:
      - "80:80"
      - "443:443"
      - "8080:8080"
    command: 
      - "--api.insecure=false" 
      - "--providers.docker"
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock
      - "./letsencrypt:/letsencrypt"
      - /home/pidadm/traefik.yml:/etc/traefik/traefik.yml
    networks:
      - traefik-network

  myservice:
    image: myservice:latest
    container_name: myservice
    restart: always
    networks:
      - traefik-network
    labels:
      - "traefik.enable=true"
      - "traefik.http.routers.myservice.entrypoints=websecure"
      - "traefik.http.routers.myservice.tls=true"
      - "traefik.http.routers.myservice.tls.certresolver=myresolver"
      - "traefik.http.routers.myservice.rule=Host(`myservice.com`)"
      - "traefik.http.services.myservice.loadbalancer.server.port=8443"

networks:
  traefik-network:
    name: traefik-network

And my entrypoints:

entryPoints:
  web:
    address: ":80"
    http:
      redirections:
        entryPoint:
          to: websecure
          scheme: https
  websecure:
    address: ":443"

Maybe somebody has an idea where I went wrong, thank you!

Why don't you use port 8080 for your internal application and let Traefik handle TLS/SSL?

How does your application set up it's TLS? Is is a custom created certificate? Maybe try insecureSkipVerify.