Hi Ernest,
We chatted with Kinsta about this because we could not find further info in their error logs. Here is what they said.
“When a POST request is used, unlike GET, there is data being exchanged between the server and the browser (eg: some parameters will be sent to that URL, a good example of a type of page that would use POST instead of GET is a contact form, where the message would be sent in the POST request). So it could also be due to the contents of the POST request, as the script (in this case /wp-json/ajax-search-pro/statistics/interaction/add) may have received data that it doesn’t know what to do with, and in this case, a generic 500 error would be displayed. I have tried to access the URL from where that request was generated (/publications/ according to the log entry), and I tried to search for “test search” and didn’t get any errors, so this could indeed have been due to a request with either incorrect or malformed data, which the target script wasn’t able to process.”
When we asked if there was any more detailed info available:
“Unfortunately not, I do not see anything in the error log related to this. Your WordPress’ installation’s debug.log is also not showing anything related to that specific request (you can confirm this in the /wp-content/debug.log and debug.log.1 files). So it does look like it was something malformed, maybe from a bot/automated request.”
We’re sorry that there isn’t more that I can provide.