Unable to renew Let's Encrypt cert after domain name change


I did a domain name change (let’s say from old.fr to new.com) using Virtualmin and now I am unable to get a cert for new.com. It looks like Virtualmin (and/or Let’s Encrypt) thinks I still am with old.fr:

ssl.CertificateError: hostname ‘www.new.com’ doesn’t match either of ‘old.fr’, ‘www.old.fr

After trying some times, I did suppress the .well-known folder and certs in the main folder, I did re-generate self-signed certs, I also disabled SSL and re-enabled SSL for these domains to no avail, I still get that reference to old.fr … I guess there is some cache or config file somewhere that was not changed by the “rename” operation …
Any idea where I should look ?