By default, pre-certificates are also shown on crt.sh, so you'd need to divide the number by 2. I.e., not 10 but 5 certificates were issued on 26 and 27 december. (Which makes sense, as the duplicate rate limit is 5 per week.)
There's no such field. That's not publicised by Let's Encrypt.
No, it's not. Also, the crt.sh output looks more like a very bad and malfunctioning or misconfigured ACME client trying to get a certificate repeatedly every minute or so! That is NOT what is supposed to do. The ACME client should check if a certificate is due for renewal, usually 60 days after issuance and only IF it's due, renew it. NOT every single minute of the day.
Also, we're lacking seriously in information here, as you haven't filled out the questionnaire which should have been presented to you when you opened a new thread in the #help section. Let's pull that questionnaire up again anyway: (some questions already have been answered, but for completeness, please fill them out again anyway)
Please fill out the fields below so we can help you better. Note: you must provide your domain name to get help. Domain names for issued certificates are all made public in Certificate Transparency logs (e.g. crt.sh | example.com), so withholding your domain name here does not increase secrecy, but only makes it harder for us to provide help.
My domain is:
I ran this command:
It produced this output:
My web server is (include version):
The operating system my web server runs on is (include version):
My hosting provider, if applicable, is:
I can login to a root shell on my machine (yes or no, or I don't know):
I'm using a control panel to manage my site (no, or provide the name and version of the control panel):
The version of my client is (e.g. output of
certbot --version or
certbot-auto --version if you're using Certbot):