Hi - try these steps:
On your iPhone, in the App Store app:
- Tap on Updates (tab);
- If updates are available, tap to update individual apps or tap on Update All (upper-right);
On your iPhone, in the Watch app, go to: My Watch (tab):
- For each affected app, tap on the app name, then turn off Show App on Apple Watch;
- Wait for a few moments, then turn the option on again.
Restart both your iPhone and your watch. Turn both devices off first, then restart your iPhone before restarting your watch:
- To turn your watch off: press and hold the side button until you see the Power Off slider; drag it to turn off.
- To turn it back on: press and hold the side button until you see the Apple logo.
More information:
Get help installing a third-party app to your Apple Watch - Apple Support