Hello Gamada2010,
Thank you for reaching out to Apple Support Communities, and we'll be happy to help in any way we can. We understand you're having issues with the World Time Watch Face. Have you tried restarting your watch and iPhone? This is a small step that corrects s multitude of issues:
Restart your iPhone - Apple Support
Restart your Apple Watch - Apple Support
If the issue persists, and your iPhone needs updating to iOS 15.6, do you have a recent backup for the data in your iPhone in iCloud or your computer? If not, we recommend that you create one as described here: How to back up your iPhone, iPad, and iPod touch - Apple Support
Then, update your iOS as outlined here: Update your iPhone, iPad, or iPod touch - Apple Support
After that, update your watch to the latest version to see if this resolves the issue: Update your Apple Watch - Apple Support
We hope this helps.
Cheers!