Girls, hi, it's normal that the child has been stuffy for three weeks …

Girls, hi, it's normal that the child has been stuffy for three weeks already, he can't breathe properly, there is a feeling that it's blocked deep inside, he rubs his nose and sleeps poorly at night. I spray a physical solution and if there are phlegm droplets, I suck them out with an aspirator but in most cases there are no phlegm droplets. The pediatrician said that this is normal for their age, that not everything is fully formed yet. What do you say, who had such a thing, what did they do?