Error 502 Bad gateway.!

Contact them again. Provide the information below to them. They can substitute the 64. address themselves in the curl command and verify their server is responding with a 502 error. Or you can set the entry to :grey: so the IP will show up as 64. to ease their minds (and the problem will still be on their origin) and after needlessly exposing your origin IP you can then change the record back to :orange: once they fix the problem which exists squarely at the origin.

curl -Ik --resolve

HTTP/2 502
server: nginx
date: Wed, 16 May 2018 20:43:18 GMT
content-type: text/html
content-length: 166
x-xss-protection: 1; mode=block
x-content-type-options: nosniff