On a new install (copy of an absolutely fine-working PW) the search is not working. And it's really strange: same server, same PHP versions etc.
The q parameter is not recognized by PHP. I tried to echo $_GET["q"] as well, but the var is empty.
The search URL is just domain.tld/search/ - instead of domain.tld/search/?q=hello
If I manually add the param in the URL: /search/?q=something, the search results are shown as expected. Error log doesn't show anything.
I also checked any .htaccess files, whether something else hijacks the q param for mod_rewrite - nothing.
Any ideas where to look further?