This line in SearchAndFilter::check_posts is not correct:
$this->urlparams .= "post_types=".$post_types;
as WordPress will ignore the post_types variable. Under certain conditions this leads to the wrong template file being selected or even the wrong search results.
I can submit a PR if you like: I suspect tho you may not be happy with the disconnect between your own variable names names and the default names you're later injecting into the URL.
This line in SearchAndFilter::check_posts is not correct:
as WordPress will ignore the post_types variable. Under certain conditions this leads to the wrong template file being selected or even the wrong search results.
I can submit a PR if you like: I suspect tho you may not be happy with the disconnect between your own variable names names and the default names you're later injecting into the URL.