Sinus after covid vaccine. Vaccine?

Hi, Its been more than 3 months since I have recovered from COVID . I took covishield a week back and developed sinus pain and mucus which is white and yellow. There is pain in upper jaw sometimes between the eyes and then it goes in the morning, after meals it increases. There is headache sometimes just above ears on either side and sometimes nose gets blocked. I tried steam inhalation with karvpul capsule , they provide relief for some time then same situation.i am also otrivin daily nasal wash which gives relief for few minutes. I saw ENT two months back as precuationary checkup for mucor but my KOH came negative, I don't have diabetes. However endoscopy confirmed I have 4 nasal polyps. What could be the reason of sinus after vaccine?