Let's Debug

Test result for clemsonlca.org using http-01

A private, inaccessible, IANA/IETF-reserved IP address was found for clemsonlca.org. Let's Encrypt will always fail HTTP validation for any domain that is pointing to an address that is not routable on the internet. You should either remove this address and replace it with a public one or use the DNS validation method instead.
192.168.86.29
A private, inaccessible, IANA/IETF-reserved IP address was found for clemsonlca.org. Let's Encrypt will always fail HTTP validation for any domain that is pointing to an address that is not routable on the internet. You should either remove this address and replace it with a public one or use the DNS validation method instead.
fe80::e654:e8ff:fea0:a7fe

Submitted Dec 9 22:45:48 2021. Sat in queue for 2ms. Completed in 0s. Show verbose information.