Hi,
I see you may be using SG Optimizer, unfortunately that one has bugs (maybe they are fixed now) with CSS combine feature, where some files are not parsed even though they are queued for minification. There are two ways to resolve the issue:
– Try turning off the CSS combine feature in SG Otpimizer
– Or switch the CSS loading method to inline, that will very likely help.
Of course after both changes make sure to clear all layers of cache.