Typical Epi site on the DXP. Have not been able to reproduce locally.
There is a scheduled job that pulls data from an external API using HttpClient and then indexes through Find-client.
Sometimes the job logs this sort of merged into the Execute result string:
The remote server returned an error: (502) Bad Gateway.
Server Error
502 - Web server received an invalid response while acting as a gateway or proxy server.
There is a problem with the page you are looking for, and it cannot be displayed. When the Web server (while acting as a gateway or proxy) contacted the upstream content server, it received an invalid response from the content server.
I see the Application Insights key from the script in the "embedded" error page and it comes from the application that holds the job.
Anyone been digging around similar thing and found something?