Accessory maxillary ostium- recirculation

Hi, I always had very minor symptoms due to dust mite allergy. Then went throw septoplasty and turbinectomy 11 months ago. First 3 months- Feeling great, Later on I started having constant runny nose, 2 months of Flonase made the symptoms worse. Post nasal drip, Poor breathing, Congestion and constant runny nose. CT scan revealed left side accessory maxillary ostium and recirculation, My ENT thinks that׳s main reason for the symptoms, Even though symptoms are on both sides. FESS has been offered