WordPress: Every time redirects to the login screen

I already had this problem for some time on my website. Every time we went into the administration area (wp-login.php) and entered some options, was redirected to the login screen again. It was a bag for sure.

I researched a lot and found the problem. After performing the procedures described in the post Optimizing the Band Site, which explains how to use the file. "htaccess", I discovered that the problem occurred due to the command line below:

AddOutputFilterByType DEFLATE application/x-javascript text/css text/js text/javascript text/html text/plain text/xml text/php

I realized that the "text / php" was responsible for this behavior. I removed this option from the list, keeping everything else and the problem stopped happening.

Final result:

AddOutputFilterByType DEFLATE application/x-javascript text/css text/js text/javascript text/html text/plain text/xml