Starting on July 8th, 2021, at approximately 8:50pm ET, a small number of Pages sites using reverse proxies began returning error codes for consumer-facing requests. Publishing of content was unaffected. All sites were restored by July 10th at 12:00pm ET.
A change in the IP addresses of Yext's Pages serving infrastructure occurred on July 8th. This change was not picked up by the reverse proxies for some sites, so they continued to send requests to the old IP addresses, resulting in an error.
The affected customers were contacted and assisted in refreshing the DNS caches for their proxies, restoring service.
We have requested that affected clients update their proxies to make use of the DNS TTL on our infrastructure to pick up any future IP changes, and our documentation will be updated accordingly.