I have been working on this issue for a few hours and I have searched the forums. I fear this situation is unique to my site seeing as I am using a premium and complex theme purchased on ThemeForest called Sahifa.
My site is http://www.orec.ca. For reasons I cannot figure out, only some parts of my child CSS are getting applied while others are ignored completely.
I am trying to change the sub menu padding and header padding.
It appears that something went wrong after my last theme update but I don't know where to look to resolve this issue. Any pointers are appreciated!