I would like to let the user input the post id and search for it. Right now in this case the search returns nothing, everything else works fine. I checked the settings and documentation but could not find anything related, please suggest a soultion.
On the General Options -> Sources panel you can enable searching posts by their IDs, here: https://i.imgur.com/466vaVI.png
That should resolve this issue.
thanks for your answer. I already activated this option before. Index is fresh. Could you offer another solution? There should not be any issues with other plugins because everthing else works fine.
I’m not sure what the issue is then, it works okay on the test servers. Can you add temporary back-end and FTP access? I would like to check the query directly.