These websites had Let's Encrypt certificates installed through Asustor's control panel, and everything was working perfectly for years. I needed to add the following websites:
For these new websites, I wanted to add certificates. When I attempted to add a new certificate that would serve all the websites, I received a message stating that the certificate already exists. To overcome this, I deleted the existing certificates and tried to create new ones using the Certificate Manager in ADM 4.x.
Initially, I started receiving an error that "chotorovi.myasustor.com" is not valid and should be accessible through port 80. I tried replacing it with several other previously configured and working domains (fb.place.bg, myhomenas.chotorovi.com, ...), but the error persisted for each of them.
After multiple attempts, I am now getting the following error: "The number of certificates issued by Let's Encrypt for your domain name has reached its limit. (Ref. 5017)" and I can't do anything further.
I seek assistance to overcome this issue as the websites are live with high traffic, and now all of them display an error that the connection is not secure. Some of them cannot be accessed at all (You cannot visit myhomenas.chotorovi.com right now because the website uses HSTS).
I don't see a reason for Let's Encrypt to deny issuance due to any limit. Sometimes there is a delay on the public logs but for now I don't see too many.
And, sometimes NAS devices have their own limit checks and this is possibly what is happening.
One likely problem is your puzzle.place.bg is pointing to a different IP than all the others. If you keep retrying and failing Let's Encrypt will temporarily block you for an hour. The LE message in this case is not what your NAS is showing so hard to know for sure.
dig +noall +answer puzzle.place.bg
puzzle.place.bg. 239 IN A 18.104.22.168
dig +noall +answer chotorovi.myasustor.com
chotorovi.myasustor.com. 300 IN A 22.214.171.124
(all your other place domains match this one)
As an aside, your place.bg root domain seems to be a shared name with a large number of certs issued. And, LE has limits on how many certs it will issue per root domain. But, almost all the certs I saw were issued by cPanel so would not be a problem for LE. If more people using place.bg start using LE this could be problem that the owner of that domain would need to ask for a rate limit exclusion (or to be added to the public suffix list).