Old background images are displayed even after cleaning cache!

Something very funky going on with my assets. So I have defined background images in my scss. Recently I swap images and left same name. After updating the site I can still see the old image instead of new. Now the funny part:
When I type the direct url to the image in the browser I will see old image. When I access the server from FTP, I can see new image (same path) ! It drives me crazy because this doesn't even make any sense. And yes, I did clean the cache completely.

Help!

Cleared the browser cache too?

What if you use another browser, or incognito mode?

if the direct URL to the image via the browser is showing the old image, then the webserver is probably sending header tags with this image to tell the browser that it's not changed, and to use the cached version if available. This is probably not a Grav issue, but more a webserver configuration or reverse proxy setting this settings.

@rhukster right. This might be my NGINX configuration. Let me have a look.