Yes, it has happened to me several times when my net was down. The way to avoid that is when your internet service goes down, click on your WiFi icon menu and select "Turn WiFi Off". Then your apps (the ones that do not need an internet connection) will work as before.
When your service resumes, go back and turn WiFi back on. I know that sounds a bit unusual but it works. When my service goes down I use my iPhone's hot spot. Since I have unlimited calls and data, I can keep the connection up that way.