The current status as reported by the Let's Encrypt status page is Partial Service Disruption as at 2019-07-31 20:23:57.115 +0000 UTC. Depending on the reported problem, this may affect certificate issuance. For more information, please visit the status page.
https://letsencrypt.status.io/
Challenge update failures for gofitnessmind.com in order https://acme-staging-v02.api.letsencrypt.org/acme/order/5751349/43358080
acme: error code 400 "urn:ietf:params:acme:error:dns": DNS problem: NXDOMAIN looking up TXT for _acme-challenge.gofitnessmind.com