If you’re experiencing two or more, Apple recommends unpairing your Apple Watch from your iPhone. After that, you’ll need to verify that iCloud is working correctly and create a new back-up in the cloud, or on your Mac or Windows computer using your USB charging cable. After you’ve got an up-to-date backup of your iPhone and Apple Watch data (Apple Watch is included in back-up files of a paired iPhone), you’ll need to open the Settings app on your iPhone > tap General > Reset > Erase All Content and Settings.
After that, you’ll need to turn on your iPhone and restore it from iCloud (or your computer). Once restored, open the Watch app on your iPhone and hit the Start Pairing option. Wait until the app locates your Apple Watch, then tap Restore from Backup. Choose the most recent backup to restore all of recent workout and health data.
It’s a pretty serious process. Apple includes more details about every step on the new support page.
Apple has already rolled out iOS 14.0.1 and watchOS 7.0.1 worldwide. While these updates don’t fix all of the problems listed above, they do quash a number of bugs and improve the general stability of the latest operating systems. If you haven’t already, it’s well worth updating as soon as possible.
With any luck, Apple will be able to eradicate all of the issues listed above in future updates.