windows python http.server can not be reached

I am used to run python3 -m http.server from GNU/Linux systems to serve files locally.

I had to do this on windows, and although python replies:

Serving HTTP on 0.0.0.0 port 8000 (http://0.0.0.0:8000/) ...

I can not reach the server.

Browsers give this:

| address                 | Firefox response | Chrome response         |
| ----------------------  | ---------------  | --------------          |
| http://localhost:8000/  | nothing          | ERR_EMPTY_RESPONSE      |
| http://0.0.0.0:8000/    | nothing          | ERR_ADDRESS_INVALID     |
| http://127.0.0.1/       | nothing          | ERR_CONNECTION_REFUSED  |

I tried to deactivate the firewall and to add rules allowing TCP connections to this port (not 80, as shown above), but did not succeed. I am not a windows user, so I might have missed something evident...

Other questions (1, 2) seem to say that it is easy.