Same for my baby and I asked my paediatrician as appointment was near. Paediatrician explained that mucus is a response to an environmental stimuli, for example dust. Put saline and suck mucus out! No need try too hard if cannot come out, especially if baby is not bothered. I regularly wipe down all the dusty areas and do a thorough clean+change bedsheet on weekly basis - my baby no longer had this. Bring to doc if baby shows discomfort!
My baby had blocked nose around 2 weeks old too. Called the clinic to see a GP but they said baby is too young to take medicine and it would be useless to see a doctor. There’s no medication for baby too. Only can use the suction tube to suck out any mucus (if got) to clear baby’s nose.