第一次请求后Tomcat空POST主体

I have an absolutely weird problem: I have a service written in php where I get the user request from:

$input = json_decode(file_get_contents('php://input'), true);

Everything is fine but one user is unable to use the service, because $input is not only at first request. We spent three days trying to fix this, nothing helps. I logged everything I could and found the difference between $_SERVER arrays I get:

in case of "good" request the [HTTP_CONTENT_ENCODING] IS NOT SET
in case of request with empty body am getting [HTTP_CONTENT_ENCODING] = gzip

I'm really confused with all of that but maybe there is something we could change it tomcat to fix this?

So we solved the problem. As we all suspected the problem was on tomcat side... And it solved by truning of something called zipMode...