This has only happened to me since I got my S7. I'll set up Google maps and I'll lock my phone while I'm driving. After a few minutes it will say that I have lost gps signal. How do i stop it from happening?
When Maps is no longer the foreground app, it can lose GPS (because it stops looking), but the part that notifies you that it lost the signal isn't disabled so you get the notification. That's called an oops in programming. With an app that large, some things just don't get found before release. Email apps-help@google.com and let them know.