The domain theisifiso.com is being served through Cloudflare CDN. Any Let's Encrypt certificate installed on the origin server will only encrypt traffic between the server and Cloudflare. It is strongly recommended that the SSL option 'Full SSL (strict)' be enabled.
https://support.cloudflare.com/hc/en-us/articles/200170416-What-do-the-SSL-options-mean-
Challenge update failures for theisifiso.com in order https://acme-staging-v02.api.letsencrypt.org/acme/order/5751349/6317907753
acme: error code 403 "urn:ietf:params:acme:error:unauthorized": Incorrect TXT record "1_IGqtENjNs5NwNuAdo_D8gg7aQ0zTHm5q3aAb_A5EY" (and 1 more) found at _acme-challenge.theisifiso.com