QWebEngineUrlRequestInfo::redirect(...) to custom scheme results in ERR_UNSAFE_REDIRECT

When I execute 

QWebEngineUrlRequestInfo::redirect(...)

withing my custom URL interceptor, then it just seems it is not working. My web view just displays "cannot load" error page and URL of the view is not changed to "redirected" but keeps original one.

For example, in my app I detect in interceptor that my original URL is "seznam.cz" and if it is, i redirect with the above method to "xyz.cz" and it seems that this is not happening at all, I still see "seznam.cz" in my web view.

Have I misunderstood the purpose of redirect(...) method?