I'm developing a plugin, that should display content according to two optional parameters in the URL. The following URL should all be treated by the plugin:

/pluginpage/
/pluginpage/value1/
/pluginpage/value1/value2/

Now I have put in place these things:

• A page with a shortcode [myplugin] and the URL /pluginpage/
  • The shortcode that displays the content taking the parameters from the $_GET variable
  • The plugin works if the URL looks like /pluginpage/?param1=value1&param2=value2
• Two rewrite rules in place, that match the three URL patterns to the page with the shortcode

add_rewrite_rule('^(pluginpage)/(.*)/?', 'index.php?name=$matches[1]&param1=$matches[2]', 'top');
add_rewrite_rule('^(pluginpage)/(.*)/(.*)/?', 'index.php?name=$matches[1]&param1=$matches[2]&param2=$matches[3]', 'top');

The rewrite rules work, but not as expected. When navigating to /pluginpage/value1/ or /pluginpage/value1/value2/ the page with the shortcode is displayed, but there is a redirect to /pluginpage/ and the parameters are lost during the redirect.

There is a missing piece that tells wordpress to not redirect from /pluginpage/value1/ to /pluginpage/. What exactly is missing?

Or might there be a better approach by mapping the URLs directly to the plugin without using a page and a shortcode?

This question is quite similar, but the answers are lacking important details, and therefore was not helpful in my case.

Thank you for any help.