Hi
The following steps may help:
Check that Bluetooth and Wi-Fi are enabled on your iPhone:
- Settings > Bluetooth.
- Settings > Wi-Fi.
Restart both your iPhone and your watch, turning both off together, then restarting your iPhone first:
If the issue persists, next unpair and re-pair your watch:
If you cannot unpair your watch via the Watch app on your iPhone and you cannot access your watch, instead follow these steps to erase it before re-pairing:
- Connect your watch to its charging cable, with power connected.
- Press and hold the side button until you see the Power Off slider.
- Press firmly on Power Off (do not try to slide it - just press down more firmly than a normal tap) and then tap on Erase all content and settings.
- Re-pair your watch using the Watch app on your iPhone, choosing to Restore from Backup if offered the option.