If you want to use the built-in Workout app on your Apple Watch, you can be limited to sending that data elsewhere. I love Runkeeper as a place to store all my runs, but they won't read the maps from the Activity app.

If you have a problem like this, check out RunGap. By unlocking the $1.99/3 month in-app purchase, you'll be able to export your data from the Health app (which is where the Activity.app records the data) to multiple other services.

With RunGap 2.9 (and iOS 11), they also will send the map/GPS information as well. This means you can use the built-in watch workout app, but have all of your data end up (including maps) end up in Runkeeper, Strava, etc.

RunGap is free on The App Store.