flush_rewrite_rules is called on every page load

The script /pwa-for-wp/service-work/class-service-worker.php has a method pwaforwp_onesignal_rewrite which is called every time a page is loaded. This results in rewriting the .htaccess file contents to disk. This is bad behavior and also results in errors when used in combination with WPML. For some reason, WPML adds the language to the RewriteBase, resulting in a duplicate Rewrite block. This is a known bug when plugins update the .htaccess file too often.

Also, the code for the method seems wrong:

function pwaforwp_onesignal_rewrite(){
            flush_rewrite_rules();
            // Flushing rewrite urls ONLY on activation
            global $wp_rewrite;
            $wp_rewrite->flush_rules();
                        add_rewrite_rule("onesignal_js/([0-9]{1,})?$", 'index.php?'.pwaforwp_query_var('sw_query_var').'=1&'.pwaforwp_query_var('sw_file_var').'='.'dynamic_onesignal'."&".pwaforwp_query_var('site_id_var').'=$matches[1]',>
            add_rewrite_rule("onesignal_js/?$", 'index.php?'.pwaforwp_query_var('sw_query_var').'=1&'.pwaforwp_query_var('sw_file_var').'='.'dynamic_onesignal'."&".pwaforwp_query_var('site_id_var').'=normal', 'top');

                }

Calling the method flush_rewrite_rules already calls $wp_rewrite->flush_rules();, so this code seems to do it twice!

The pwaforwp_pushnami_rewrite method has the same behavior, but adding this method to the init hook is disabled by an option, so it’s not triggered by default.