3 month old congested since birth

Hey mamas, my 3 month old has sounded congested since birth. Not in his chest but nasal congestion. I have taken him in to his pediatrician multiple times and its constantly being brushed off. My son developed stridor breathing sounds when he was about a week old so we have seen an ENT who has done a nasal scope and he said everything looks good structurally and diagnosed my son with reflux as we as sleep apnea after doing a sleep study. The stridor is gone now at 3 months but the nasal congestion is still there. We use saline and a suction multiple times a day and nothing ever comes out. Maybe just a small amount. He never has a runny nose either. Im starting to notice now hes coughing as well but that just started a couple weeks ago. He is taking medication for the reflux which tbh im not really sure its helping much at all or not. The weird thing is i dont think hes actually congested at all, just sounds it. He was eating fine up until last week and now hes starting to struggle with the bottle a bit and needs to take frequent breathing breaks so he can breathe through his mouth. Im very worried. Any other moms deal with this?