Thanks for your help ! I does make sense to me.
I didn’t give you the domain name so here is it: https://www.lr-agenceweb.fr
I already had certificates working before for this domaine name so I guess the regeneration will still use the same path as I filled in my Nginx virtual host:
Extract of my vhost:
ssl_certificate /etc/letsencrypt/live/www.lr-agenceweb.fr/fullchain.pem;
ssl_certificate_key /etc/letsencrypt/live/www.lr-agenceweb.fr/privkey.pem;
The only thing I didn’t do was to restart Nginx.
I will try it now.
Edit: After reloading Nginx, the expiration date was updated properly ! Thanks again !