Well, i've installed Gitea and followed the installation process.
i've followed the process after configuring the domain (Stop then Start)
After a few seconds, the gitea page is enable and the login screen appears.
but, when my shell sessions logs out, it seems that the gitea process which was lauched in the background is killed and the site is no more served with an awfull "bad gateway" message.
When loggin in again and starting again gitea everything is online again until i get connected to the server.