Search&Promote traceability on issues

Hi,

We've integrate Search and Promote within our site, on publisher following the configurations detailed on 

https://experienceleague.adobe.com/docs/experience-manager-65/administering/integration/search-and-promote.html?lang=en#configuring-the-data-center

As we are behind a internet outbound proxy both com.day.commons.httpclient and org.apache.http.proxyconfigurator were configured.

Search box and result sets work ~95% of the time.

The issue is that for the remaining 5% of the time, the search box don't appear, and users are presented with a 'Search is current unavailable message'

We've configured logs for 'com.day.cq.searchpromote', 'com.day.commons' and 'org.apache.http' and set those to trace level, isolated the server, so this S&P page be the only thing running.

When an error is received no log is being written.

Standard error.log and stdout don't have more information.

There is something else to look up that I'm missing? Other than check network logs with a tool like Wireshark, what alternatives exists? 

Does AEM provide another logger I'm missing? 

Best Regards.