Apple Watch GPS only tracks part of workout route

When recording a run or walk, my Apple Watch sometimes does not record the entire route on the map, as shown in the Fitness app on the iPhone. Typically in such cases, only half or a smaller part of the route is recorded, even though the correct distance, time, and all other parameters have clearly been recorded. This is irritating in and of itself, but even more frustrating in that it also screws things up when exporting the workouts to third-party sites for analysis and statistics. I've seen people that have had issues with the Watch only setting the "start" point for a workout, and my issue seems similar but not identical. Any help would be appreciated.

EDIT: I've checked that all Location Services settings are correct