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.
View attachment 130390
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