Apple Watch workouts missing GPS data for some users
A number of users on watchOS 7 are reporting that their Apple Watches are failing to record GPS data from their walk workouts, including when using the Strava fitness app.

Some Apple Watches are reportedly not recording GPS route data
Apple's support forums currently lists over 1,300 people claiming to have found that the Apple Watch Outdoor Walk activity is failing to record GPS data when people do not also have their iPhone with them. In most cases, the Health app reportedly records the starting point of a walk, but nothing for the rest of the route.
In some cases the data is not being sent to the Strava fitness app. However, other people say that route data is not being recorded in Apple's Health app either.
The Apple support thread includes people saying they've had this problem with watchOS 7 from Apple Watch Series 3 to Apple Watch Series 6. Apple has yet to comment publicly on the issue, but a users in the thread claim to have been told different answers from Apple Support.
Some say that Apple has promised a solution in an update to watchOS 7. Others have said that support staff have said that the solution depends on Strava.
In the thread first spotted by MacRumors, some users say backing up, unpairing and re-pairing the Watch fixes it.

Some Apple Watches are reportedly not recording GPS route data
Apple's support forums currently lists over 1,300 people claiming to have found that the Apple Watch Outdoor Walk activity is failing to record GPS data when people do not also have their iPhone with them. In most cases, the Health app reportedly records the starting point of a walk, but nothing for the rest of the route.
In some cases the data is not being sent to the Strava fitness app. However, other people say that route data is not being recorded in Apple's Health app either.
The Apple support thread includes people saying they've had this problem with watchOS 7 from Apple Watch Series 3 to Apple Watch Series 6. Apple has yet to comment publicly on the issue, but a users in the thread claim to have been told different answers from Apple Support.
Some say that Apple has promised a solution in an update to watchOS 7. Others have said that support staff have said that the solution depends on Strava.
In the thread first spotted by MacRumors, some users say backing up, unpairing and re-pairing the Watch fixes it.
Comments
To be honest, I've never looked at the GPS data until recently (I've always relied on Runkeeper for this functionality).
I assumed that all Apple Watches with GPS recorded this data.
Edit: I also noticed my workouts were missing GPS data and some were missing heart rate data. I just did a full restore on my watch and did a short workout and that workout did show up on my phone. It looks like the issue was with the watch then. We’ll see what happens tonight with my real workout. The two missing days of workouts are still no there though. I’ll have to manually add them.
AND
my WatchOS 6 GPS tracks have disappeared (the map is not displaying at all for all my old workouts)
iPhone 11 Pro and Apple Watch Series 3
I upgraded to the public beta of WatchOS 7.1 to see if that helped => same result
battery life (which is also a disaster on 7.0) is greatly improved with the beta version though
Until yesterday, the last recording of my walks from my Series 4 AW was last Friday. My walks on Saturday through Monday weren't preserved in other apps on the iPhone that I rely on.
For some reason, the iPhone now has the information from Tuesday.
I also noticed for the first time (maybe it was always there), there are entries in the Health app for V02. Hopefully they are not accurate, since from the number it's giving me, I should be nearing death. When I get the Series 6 early October, I'll likely get a more accurate value -- I hope they're better.