I strongly suggest that you run a manufacturer's GPS test on your watch. Firstly make yourself a developer by going to Settings > System > About and tapping the build number 7 times. You will find a new Developer options menu item. Select this, and scroll down to Manufacturer service tool and select it. You will find a GPS Test option which you can run (you need a clear view of the sky, not indoors). This will test the standalone GPS in your watch and its ability to lock onto satellites. If your watch passes this test (ie. finds satellites) then you should be able to use untethered GPS in your fitness app. 

Important: if your watch initially gets a GPS fix from your connected phone, then it will not retain the fix once phone and watch disconnect - for example if you go running. I wrote a Reddit post with some possible solutions. Also, as I mentioned in an earlier post, if your watch passes the GPS Test above then Wear Logger will almost certainly work for you to track your activities and upload to Google Fit and/or Strava.

Hope this helps anyone still having GPS problems. Hopefully we will get a proper fix from Google at some point.