targettec.ddns.net is currently affected by Let's Encrypt-based rate limits (https://letsencrypt.org/docs/rate-limits/). You may review certificates that have already been issued by visiting https://crt.sh/?q=%targettec.ddns.net . Please note that it is not possible to ask for a rate limit to be manually cleared.
The Duplicate Certificate limit (5 certificates with the exact same set of domains per week) has been exceeded and is affecting the domain "targettec.ddns.net". The exact set of domains affected is: "targettec.ddns.net". It may be possible to avoid this rate limit by issuing a certificate with an additional or different domain name.