Congestion caused by Kefir?

I am noticing that I am very congested. I am wondering if this could be caused by the milk kefir I have started drinking? I used to get this way from milk which is why I went dairy free a few years ago.

I have not been able to get raw milk consistently so I have been making my Kefir with non-homogenized organic milk as Uny suggested. Could this be the problem, not using raw milk?

I have been letting the kefir sit for 24 hours before I drink it. I am wonder if I leave it for 48 hours instead if that will help? Or if there are others things I could do? I read that sometimes you can stain the Kefir after 24 hours bur then leave the strained kefir on the counter at room temperature for longer

If anyone has had the same experience of any ideas I would appreciate it.

Thanks so much,
Jackie