It happened after an upgrade. Everything I've read says the solution lies in recalibration. There is no way 17,000 steps can be recalibrated into anything close to 17 miles. That number of steps is closer to 7.9 miles.
The first (and simplest) thing to try if something isn’t working right is to restart your Apple Watch and its paired iPhone. If necessary (device not responding), try a forced restart. Both methods can be found here:
How to restart your Apple Watch - Apple Support
Restart your iPhone - Apple Support
If that doesn't help, the next steps would be to unpair and pair your watch again and restore from the backup just created. This should result in no loss of data. It deletes all temp and corrupted files and re-indexes the file system.
Unpair and erase your Apple Watch - Apple Support
You can further improve its accuracy using these tips.
Get the most accurate measurements using your Apple Watch - Apple Support
You should also make sure your watch is calibrated:
Calibrating your Apple Watch for improved Workout and Activity accuracy - Apple Support
How is it possible that my Apple Watch shows 17,834 steps and right underneath that it says I walked 17.20 miles? Even if I had walked 17, 000 steps (which I didn't ) that would roughly equal 7.9 miles. My watch is completely haywire.
