Docker doesn't Run and Immage after Downloaded

Hello to everybody

I have the follow problem, I installed on my raspberry pi docker.

docker --version   

Docker version 19.03.12, build 48a6621

pi@raspberrypi:~ $ docker version
Client: Docker Engine - Community
Version: 19.03.12
API version: 1.40
Go version: go1.13.10
Git commit: 48a6621
Built: Mon Jun 22 15:53:00 2020
OS/Arch: linux/arm
Experimental: false

Server: Docker Engine - Community
Engine:
Version: 19.03.12
API version: 1.40 (minimum version 1.12)
Go version: go1.13.10
Git commit: 48a6621
Built: Mon Jun 22 15:47:00 2020
OS/Arch: linux/arm
Experimental: false
containerd:
Version: 1.2.13
GitCommit: 7ad184331fa3e55e52b890ea95e65ba581ae3429
runc:
Version: 1.0.0-rc10
GitCommit: dc9208a3303feef5b3839f4323d9beb36df0a9dd
docker-init:
Version: 0.18.0
GitCommit: fec3683

I test that all it works fine with hello word image.
I run it and that’s the result:

pi@raspberrypi:~ $ docker run hello-world
Unable to find image ‘hello-world:latest’ locally
latest: Pulling from library/hello-world
4ee5c797bcd7: Pull complete
Digest: sha256:7f0a9f93b4aa3022c3a4c147a449bf11e0941a1fd0bf4a8e6c9408b2600777c5
Status: Downloaded newer image for hello-world:latest

The same situation with tobi312/rpi-nginx, it’s downloaded but not in run, I can see stopped with

docker ps -a

Does somebody have any idea?

Thanks a lot

Best Regards

Alessandro