OverRide Css file

hy !
i make some changes in css. These changes also shown. But the problem is that when i refresh the browser almost 4th or 5th time, all changes reset. Maybe some other file override file or something else.I am changing on live site .
css min file name is ::k6xy928cti3xyi6gw71n9px0dy1xfzxh5wvftgzjwgs.min.css
nop-version :: 4.02

plz help me out.
Thanks.

No need to make two posts
https://www.nopcommerce.com/en/boards/topic/81836/css-changes-keep-reseting