Accessing subpage results in 302 response with query string dropped

Hi

I have a problem with Cloudflare (most probably). I am maintaining a site set up by somebody else and it’s probably a matter of finding the right configuration option, but looking through dashboard I couldn’t find anything relevant.

When requesting any subpage with any query params I am getting a 302 response with location header set to subpage only, without query params.
For example, domain.com/contact-us?msg=test would have response headers:

location: /contact-us/
server: cloudflare
status: 302

On root it works as expected, the response is 304 and query params are visible in the URL.

Does anybody have an idea what may potentially be causing this redirect? Where in the site configuration should I look?

Possibly the “Always use HTTPS” setting.

Whats the actual URL?