!!! I used to get that all the time! Prior to vaping, I'd always be congested. Breathed exclusively through my mouth. Once I started vaping, the congestion cleared up, my sinuses opened up and the frequency of colds diminished to the point of being nonexistent.
Along with that, though, was a perpetually runny nose. I never viewed it as a negative thing...I attributed the condition to my body ridding itself of viral infection. I have no idea why it really occurred...I just accepted it 'cause it was an improvement over having a stuffy nose.
What's remarkable is, sometime during the last few months it stopped. I hadn't noticed it until I read your post.