ERR_CERT_COMMON_NAME_INVALID on chrome

When trying to login to my website on Chrome based browsers I get the error:

Failed to load resource: net::ERR_CERT_COMMON_NAME_INVALID

On firefox it works fine, tho.
I installed certificates by certbot. My corresponding nginx settings look like:

server {
        listen 80;
        server_name pvapp.umwelt-campus.de;
        return 302 https://$server_name$request_uri;
}

server{
        # SSL configuration
        listen 443 ssl default_server;
        listen [::]:443 ssl default_server;
        add_header 'Access-Control-Allow-Origin' '*';
        add_header 'Access-Control-Allow-Credentials' 'true';
        add_header 'Access-Control-Allow-Headers' 'Authorization,Accept,Origin,DNT,X-CustomHeader,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type,Content-Range,Range';
        add_header 'Access-Control-Allow-Methods' 'GET,POST,OPTIONS,PUT,DELETE,PATCH';

        ssl_certificate     /etc/letsencrypt/live/pvapp.umwelt-campus.de/cert.pem;
        ssl_certificate_key /etc/letsencrypt/live/pvapp.umwelt-campus.de/privkey.pem;
        ...

Already tried to clear cache, clear windows ssl-cache restarted everything and renewed the certs.
Hope anyone has an idea. 🙂

Using Ubuntu 16.04.7 xenial