This scenario can come from plugins modifying your .htaccess files so as to add or improve policies, or from an old WordPress MU configuration not current due to the fact Multisite was additional. You can know everything about your server, improve particular options and down load a TXT report of https://www.tumblr.com/oxavin/783861904352411648/%E6%A0%B8%E5%BF%83%E5%8A%9F%E8%83%BD%E4%B8%8E%E4%BC%98%E5%8A%BF