WordPress CSS Support

I'm helping making some css changes to a wordpress website but change seem to get the css to render in the preview. I'm using gulp sass to compile the scss into minified css but no changes occurs, I've cleared out the browser cache many times but still no success. I am not using any plugings that use it only wp engine advanced cache options and its for a my only theme i have on the website. If you could point me in the right direction it would be much appreciated!