No response to nasal sprays. why? True?

Hi doc Me and my mother both suffer from allergic rhinitis..I get post nasal drip and she gets runny nose..both of ours symptoms get resolved if we take antihistamine like cetrizine + montelukast. But if we take fluticasone nasal spray, there is no improvement at all even after month..both of us get no relief from nasal sprays...even tried metaspray. What is the reason behind this?? Is it genetics? Or the corticosteroid is not getting absorbed? Or its getting absorbed but not producing result. I want to know for general medical knowledge that if there are no results, does it also mean that corticosteroid will be unable to produce any of the side effects since body is not responding. I know that corticosteroid used in nasal sprays is anyways local application only but it also has " increased eye pressure" as a rare side effect. Persons not responding to steroids also mean they won't respond in terms of side effects in general? Is it true? Thanks .. please explain