Nextcloud broken after renewal of lets encrypt cert

My nextcloud was running fine for some month.

I started the renewal of my letencrypt cert as ncp user on port 4443.
As far as I could see that worked fine.

After a reboot all ports were closed byside of the ssh prot.

The reason was, that the certs were no longer on
but in
the difference ist the**-0001**

My quick fix was a symlink
sudo ln -s /etc/letsencrypt/live/mydomain.yxz-0001 /etc/letsencrypt/live/mydomain.yxz

After that I could access nextcloud again.

Is this my mastake, or is this a bug?

What can I do to avoid this problem in the future?

Tx and greetings Leon