Lose wifi connection when I run iTunes

I have a weird issue. I have a 15" mid 2012 MacBook Pro. Everything was fine until I "upgraded" to El Capitan. Once I did that, every time I run iTunes, I lose wifi connectivity. The icon in the menu bar stays on, but I have no net connection at all. I have to either turn off the wifi and turn it back on again, or connect to a different access point. This is a real PITA, not to mention I'm unable to purchase anything on iTunes anymore. Any suggestions on how to fix this?