Though back when I smoked cigarettes I would have sinus congestion every winter. When I quit, it immediately went away, even though I was still smoking weed all day, every day.
I always found that weed opened my lungs and tobacco restricted them ... but I stubbornly keep smoking the latter even though I stopped using the former quite a few years ago.
I do have some sinus congestion, especially in the winter, so you may have given me a reason to finally drop the ciggies. I have found that a supplement called Serrapeptase drains and dries my sinuses pretty well but doesn’t make them too dry.