Mine finally stopped I found the app responsible. It was an mp3 download app. It was installed before lollipop and I didn't get any ads from it. Looks like lollipop is more prone to ads than kitkat
I'm getting it to. It started to happen after lollipop update. I haven't installed any new apps. Please if anyone can figure out what causes this let us know. I have a verizon galaxy s5 that was updated to lollipop ota.