I am also having the problem of not getting gps signal while using the Maps app.
When using another app like GPS Satellite it shows GPS location data is available.

But whenever I try to navigate using the Maps app, in spite of GPS being locked on, it says "No GPS signal".
The compass also doesn't seem to be calibrated. I used Compass app earlier to calibrate the compass, but now it is not showing any way to calibrate it.
The problem started after upgrading to Windows 10.
I am using Nokia Lumia 730 OS build 10.0.14915.1000