Head Congestion at End of Workout

Sometimes I feel like I have a head cold towards the end of a workout. My ears block up as do my sinuses at the back of my throat. I can breathe through my nose but my ears block up more and I feel and hear like I’m under water. I talk like I have a stuffy nose too. Takes about 20 minutes for the stuffiness to go away once I’m done. Usually happens with longer training sessions. My ears do block up fairly easy when changing elevation like driving up or down a hill but I can pop them just as easily. I can’t pop them at all when it happens during a workout.

Anyone else experience this or have an explanation? What happens during training that would cause this?

If there is one thing I’ve learned from my rotation in the ENT department this is it

1 Mix few teaspoons of regular kitchensalt in a glass of water
2 snort it out of your hand
3 use both noseholes
3 do this once or twice daily for a few weeks
4 ???
5 profit

I use a neti pot daily. I think it may have something to do with controlling my breathing. I can make it worse if I push my tongue up to the roof of my mouth and breath out.