browserSync follows my previous updates

I have just downloaded Sage starter kit and playing around with it. Everytging is working as expected and documented. But there is a problem with browserSync module.

I have created a new custom.scss file in assets/ and imported it inside main.scss file. I run ‘watch’ task from Gulp. Now I do tests by changing body background color from custom.scss :

body { background: red !important; }

The problem is when I do any modification from my custom.scss file, browserSync processes the request and says “Injecting main.css” in my browser. But the change does not effect on the page. When I do a new modification, now the previous modification has been effected on the page. This is my problem. Example :

set bg color to “blue” : no changes
set bg color to “red” : bg color becomes blue (from previous update)
set bg color to “pink” : bg color becomes red (from previous update)
… and so on

I haven’t changed anything inside gulpfile.js so I don’t think to paste it here as it untouched original version from the source.

I’m running these tools under Windows 10 and using PhpStorm as IDE and Chrome for browser.