Yes, I have same problem. Just factory reseted my Lumia 950 and the problem still occurs.
It is really annoiyng, every time i open my lock sreen, its there, sometimes multiple times. Push Ignore, it goes away til i make a call or open my phone again.
Push Open app, nothing, just goes away. And when i open my phone, again there. This is making using my phone really difficult. Been having this problem past month or so, nothing seems to help.
Havent installed any new apps or anything, one day it just was there and doesnt go away whatever you do. Need help on this.