Конфиг w3 total cache:

# BEGIN W3TC Page Cache cache
location ~ /wp-content/cache/page_enhanced.*html$ {
expires modified 36000s;
add_header X-Powered-By "W3 Total Cache/0.9.5.1";
add_header Vary "Accept-Encoding, Cookie";
add_header Pragma "public";
add_header Cache-Control "max-age=36000, public";
}
location ~ /wp-content/cache/page_enhanced.*gzip$ {
gzip off;
types {}
default_type text/html;
expires modified 36000s;
add_header X-Powered-By "W3 Total Cache/0.9.5.1";
add_header Vary "Accept-Encoding, Cookie";
add_header Pragma "public";
add_header Cache-Control "max-age=36000, public";
add_header Content-Encoding gzip;
}
# END W3TC Page Cache cache
# BEGIN W3TC Browser Cache
gzip on;
gzip_types text/css text/x-component application/x-javascript application/javascript text/javascript text/x-js text/richtext image/svg+xml text/plain text/xsd text/xsl text/xml image/bmp application/java application/msword application/vnd.ms-fontobject application/x-msdownload image/x-icon application/json application/vnd.ms-access application/vnd.ms-project application/x-font-otf application/vnd.ms-opentype application/vnd.oasis.opendocument.database application/vnd.oasis.opendocument.chart application/vnd.oasis.opendocument.formula application/vnd.oasis.opendocument.graphics application/vnd.oasis.opendocument.spreadsheet application/vnd.oasis.opendocument.text audio/ogg application/pdf application/vnd.ms-powerpoint application/x-shockwave-flash image/tiff application/x-font-ttf audio/wav application/vnd.ms-write application/font-woff application/font-woff2 application/vnd.ms-excel;
location ~ \.(css|htc|less|js|js2|js3|js4)$ {
expires -1s;
add_header Pragma "public";
add_header Cache-Control "max-age=-1, public";
add_header X-Powered-By "W3 Total Cache/0.9.5.1";
try_files $uri $uri/ $uri.html /index.php?$args;
}
location ~ \.(html|htm|rtf|rtx|svg|svgz|txt|xsd|xsl|xml)$ {
expires 36000s;
add_header Pragma "public";
add_header Cache-Control "max-age=36000, public";
add_header X-Powered-By "W3 Total Cache/0.9.5.1";
try_files $uri $uri/ $uri.html /index.php?$args;
}
location ~ \.(asf|asx|wax|wmv|wmx|avi|bmp|class|divx|doc|docx|eot|exe|gif|gz|gzip|ico|jpg|jpeg|jpe|json|mdb|mid|midi|mov|qt|mp3|m4a|mp4|m4v|mpeg|mpg|mpe|mpp|otf|_otf|odb|odc|odf|odg|odp|ods|odt|ogg|pdf|png|pot|pps|ppt|pptx|ra|ram|svg|svgz|swf|tar|tif|tiff|ttf|ttc|_ttf|wav|wma|wri|woff|woff2|xla|xls|xlsx|xlt|xlw|zip)$ {
expires 31536000s;
add_header Pragma "public";
add_header Cache-Control "max-age=31536000, public";
add_header X-Powered-By "W3 Total Cache/0.9.5.1";
try_files $uri $uri/ $uri.html /index.php?$args;
}
add_header strict-transport-security "max-age=31536000";
# END W3TC Browser Cache
# BEGIN W3TC Page Cache core
set $w3tc_rewrite 1;
if ($request_method = POST) {
set $w3tc_rewrite 0;
}
if ($query_string != "") {
set $w3tc_rewrite 0;
}
if ($http_cookie ~* "(comment_author|wp\-postpass|w3tc_logged_out|wordpress_logged_in|wptouch_switch_toggle)") {
set $w3tc_rewrite 0;
}
set $w3tc_preview "";
if ($http_cookie ~* "(w3tc_preview)") {
set $w3tc_preview _preview;
}
set $w3tc_ssl "";
if ($scheme = https) {
set $w3tc_ssl _ssl;
}
set $w3tc_enc "";
if ($http_accept_encoding ~ gzip) {
set $w3tc_enc _gzip;
}
if (!-f "$document_root/wp-content/cache/page_enhanced/$http_host/$request_uri/_index$w3tc_ssl$w3tc_preview.html$w3tc_enc") {
set $w3tc_rewrite 0;
}
if ($w3tc_rewrite = 1) {
rewrite .* "/wp-content/cache/page_enhanced/$http_host/$request_uri/_index$w3tc_ssl$w3tc_preview.html$w3tc_enc" last;
}
# END W3TC Page Cache core

Но кэш w3tc тоже чищен, плюс expires в -1 выставил.

Дальше конфиг самого сайта:

server {
server_name losst.ru www.losst.ru;
ssl on;
ssl_certificate "/var/www/httpd-cert/losst/losst.ru_le2.crtca";
ssl_certificate_key "/var/www/httpd-cert/losst/losst.ru_le2.key";
ssl_ciphers EECDH+AESGCM:EDH+AESGCM:AES256+EECDH:AES256+EDH;
ssl_prefer_server_ciphers on;
ssl_protocols TLSv1 TLSv1.1 TLSv1.2;
add_header Strict-Transport-Security "max-age=31536000;";
charset off;
index index.php;
disable_symlinks if_not_owner from=$root_path;
include /etc/nginx/vhosts-includes/*.conf;
include /etc/nginx/vhosts-resources/losst.ru/*.conf;
access_log /var/www/httpd-logs/losst.ru.access.log;
error_log /var/www/httpd-logs/losst.ru.error.log notice;
ssi off;
set $root_path /var/www/losst/data/www/losst.ru;
root $root_path;
listen 194.67.215.125:443 default_server;

include /var/www/losst/data/www/losst.ru/nginx.conf;


location = /nginx.conf {
deny all;
}

location / {

try_files $uri $uri/ /index.php?$args;

location ~ [^/]\.ph(p\d*|tml)$ {
try_files /does_not_exists @php;
}

try_files $uri $uri/ /index.php?$args;

location ~ [^/]\.ph(p\d*|tml)$ {
try_files /does_not_exists @php;
}
}
location = /robots.txt {
allow all;
log_not_found off;
access_log off;
}
location = /favicon.ico {
log_not_found off;
access_log off;
}

location @php {
fastcgi_index index.php;
fastcgi_param PHP_ADMIN_VALUE "sendmail_path = /usr/sbin/sendmail -t -i -f admin@losst.ru";
fastcgi_pass unix:/var/www/php-fpm/losst.sock;
fastcgi_split_path_info ^((?U).+\.ph(?:p\d*|tml))(/?.+)$;
try_files $uri =404;
include fastcgi_params;
}

}

Насколько я понял nginx выдает статику напрямую, в том и все дело.