Unable to forwart ports on any docker

So I was trying to set up some websites and other stuff on my Ubuntu 20.04.3 LTS Server. Different WebUI bases apps in different dockers accesed via a nginx. But I want able to connect to ANY of my dockers. After trubble shooting it seems that the port forwarding doesnt work on none of my dockers. It started with my node-red docker, nginx didnt work either and I now have setup a very simple whoami docker wis a very basic webserver running on port 8000. I'm still not able to connect to it.

If I go into the docker using an "docker exec -ti whoami sh" I am able to access the webserver via wget but not from outside the docker.

I have searched a lot and most issues where false use of the -p flag or the webserver only listening to localhost and so on. Both is not the case here.

Here is my test terminal output to show whats happening

$~ docker ps
CONTAINER ID   IMAGE            COMMAND       CREATED              STATUS              PORTS                                       NAMES
726da9705b7f   jwilder/whoami   "/app/http"   About a minute ago   Up About a minute   0.0.0.0:8000->8000/tcp, :::8000->8000/tcp   whoami
$~ 
$~ wget -O - http://127.0.0.1:8000/
--2021-10-16 23:19:09--  http://127.0.0.1:8000/
Connecting to 127.0.0.1:8000... connected.
HTTP request sent, awaiting response... Read error (Connection reset by peer) in headers.
Retrying.

--2021-10-16 23:21:21--  (try: 2)  http://127.0.0.1:8000/
Connecting to 127.0.0.1:8000... connected.
HTTP request sent, awaiting response... ^C
$~ 
$~ docker exec -ti whoami sh
/app # wget -O - http://127.0.0.1:8000/
Connecting to 127.0.0.1:8000 (127.0.0.1:8000)
I'm 726da9705b7f
-                    100% |*****************************************************|    17   0:00:00 ETA
/app # exit
$~ 
$~ cat run.sh
docker run -d -p 8000:8000 --name whoami -t jwilder/whoami
$~ 
$~ 

Proof that the server is not fixed to local host:

$~ 
$~ docker logs -f whoami
Listening on :8000
I'm 726da9705b7f
^C
$~ 
$~ docker exec -ti whoami sh
/app # ./http
Listening on :8000
2021/10/16 22:36:23 listen tcp :8000: bind: address already in use
/app # exit
$~ 
$~ 

And as far as I can tell the docker service actualy take the port:

$~ 
$~ sudo lsof -i:8000
COMMAND     PID USER   FD   TYPE DEVICE SIZE/OFF NODE NAME
docker-pr 24976 root    4u  IPv4 112329      0t0  TCP *:8000 (LISTEN)
docker-pr 24984 root    4u  IPv6 114001      0t0  TCP *:8000 (LISTEN)
$~ 
$~ 

But its still not working.

Does anybody has an idea what is going wrong I am very clueless.

Try to run this container on a different port:

$ docker run --rm -d -p 8001:8000 --name whoami -t jwilder/whoami
64a5059666e0f3db12562a44edf576336f73fcecd5e7d86c1e739259e1ffd307
$ curl localhost:8001
I'm 6a82c9e7371e

If this works, then it might be something fishy happening on the host (maybe iptables with port redirection).