NC losing SSL certificate at reboot

Hello,
I’m hosting the VM on esxi 6.7 update 3, used the script to setup the ssl certificate through let’s encrypt script (activate-ssl.sh) on my third level domain (remote.xxxxx.it), everything ok, except that when I reboot the VM, if I connect through the browser, I find non valid certificate but another certificate (released to nextcloud instead of my domain). tryed it generating another cert using xxxxx.duckdns.org, same problem, works until reboot.
Any ideas?

anyone can help?