Docker0 network down

Hello,
I’d like to clarify why in my docker host the docker0 interface is DOWN and evertything seems to work.
I’ve read about people wanting to change docker0 address, other wanted to stop it.
Why is not UP as expected ?
I needed to get docker0 address in an ansible playbook to config containers to access a host port.

In my /etc/docker/daemon.json i have this :

“default-address-pools”: [{“base”: “172.240.0.0/16”, “size”: 24}

I presume this could be relevant to the issue.

Thanks for your suggestions.