Issue with mounting webdav and self signed cert under linux

I have Nextcloud running with a self signed certificate and I wanted to mount it under linux according to the docs.
This doesn’t work for me though:
https://docs.nextcloud.com/server/17/user_manual/files/access_webdav.html?highlight=mount#id1

When I try to mount I get the following error message

/usr/bin/mount.davfs: Mounting failed.
Server certificate was missing commonName attribute in subject name

Any idea?

Thank you

Also if you need a free certificate, Let’sEncrypt

Granted, it may be because I’m running Nextcloud via a Snapcraft “Snap”, but this reply above(serverfault.com) does absolutely nothing for me but return errors and/or direct me to phantom files that do not exist on my server. I am getting absolutely no love when I try to mount via WEBDAV and get that exact same error.

I have done EXTENSIVE research and finally learned that Snapcraft.io does NOT play well with others. Especially Certbot! (I guess Certbot tries to setup certs for a basic Apache/SSL/etc setup and doesn’t even have the capability of locating anything inside of a Snap.)

I have manually located and run “sudo nextcloud.enable-https lets-encrypt” and corrected everything I can possibly find to correct… and I still get this
“Server certificate was missing commonName attribute in subject name”

Is it something that just cannot be overcome because I was lazy and used Snapcraft?
I’m just pulling my hair out after 2 months of fighting with this. (Thank GAWD this is a hobby and not my job!)

Thanks VERY MUCH in advance for any assistance, gents!

Try to google the error message on your own, if the provided link doesn’t help you. The message is absolutely clear and says that you made an error as you created your self-signed certificate, because it doesn’t contain a common name in the subject name field.

If you still get the error message you most likely haven’t correctly replaced your previous used self-signed certificate with the newly created Let’s Encrypt certificate.

You can test which certificate is used by executing the following command:

 openssl s_client -connect <fqdn-of-your-server>:443 -status