pierre75014

Hello Mikko,
It has taken a much longer time than expected. I have tried QueryMonitor, DebugTracing, changing the theme, overwriting all php files… and gave up trying to find and correct the problem. I guess it is related to some badly uninstalled plugin in the past somewhere in the database.
I have started a new test site and imported the live site’s export. Of course, I need to do this procedure in a much more precise and organized way. But, according to the first results, it works! Posts are where they should, and the search engine does work.
My solution will then be to build up a new site, check users, plugins and themes, and import the live site’s export. Then switch from one site to the other.
That will take a long time. But when every thing goes ok, I’ll post you a last message with the link to the new live site.
The last difficulties are with the limits on uploaded file size and script run time, but I have access to the php parameters on the hosting site.
Thank you for your support.
Pierre

Hello Mikko,
Well yes, filling the search forms does request the result page with an URL like https://www.mydomain.com?s=whatsoever
Not really wanting to break the live site, I will build a new WordPress site on a subdomain, post a couple of dummy articles and try to search.
If it does not work, then it must be something with php or apache on my hosting site.
If it works, I will add the few plugins I have installed on the live site, and check again the search after each change.
If it still works, then I might try to copy/paste replacing the php modules over the modules of the live site (after backing-up those modules)
And then what? Export the two databases and compare the config tables.
There a possibility to export the live database, do a massive find/replace and import most of the content into the test site.
That will take some time, a few days, maybe a week.
I’ll be back and let you know anyway.
Pierre

Thank you for your advice.
I have installed Query Monitor. Whow ! Impressive tool.
There are many database queries, but none from Relevanssi.
I will search Relevanssi forum to find any idea.
I have initiated my WordPress blog in an emergency when the former provider (“lemonde.fr”) stopped hosting the original blog. The initial database content and uploads files originate from an export of the former site. There might be some trouble in there, I need to dig.
Any way, thanks a lot again, and I’ll let you know.
Pierre

Hello Mikko,
Thank you for replying.
I have tried, installed and activated Twenty Twenty. This does not change anything. So I went back to Tiny.
Admin search works as expected.
Relevanssi’s log only displays admin search queries, and ignores user search queries. It is as if WP did not send the user request to Relevanssi.
I do not know how to solve the issue.
I have full access to the hosting site (FileZilla for FTP, PhpMyAdmin for SQL), I have been in programming (java and many other languages) for a long time but have no knowledge of PHP and all its include hierarchy.
The big difficulty is that the WP site is live.
If the problem lies in php code, I could download a fresh copy of WP 5.4 and overwrite the existing code.
If the problem lies in the database, I could update manually here or there.
The trouble is, I have no idea where to look for what.
I have deactivated other plugins without any change.
Any advise?