What type of hardware are you using: VPS bought online
What YunoHost version are you running: 12.0.14
How are you able to access your server: The webadmin
Describe your issue
We have a domain example.com, and a subdomain, ynh.example.com, which both correspond to our YNH host.
Whereas ynh.example.com is the default domain, configured in YNH, the login redirects to the apps panel on https://example.com/yunohost/ instead of https://ynh.example.com/yunohost, which leads to a certificate issue.
I tried changing the default host to example.com (which corresponds to the current visible behaviour) and back to ynh.example.com, without a noticeable change.
It used to work a few days ago, and I guess this is a consequence to a latest minor update to the yunohost main package.
Hope this helps,
Share relevant logs or error messages
Certificate is bad, as our base system has a self-signe cert. Only the subdomains have letsencrypt