Hello Fatblabs,
We understand that the App Store is not working as expected, on your Apple Watch even after completing a restart.
We'd like to provide you with some direction on how to correct this behavior:
1. Be sure you're running the latest software version. This is to ensure your device has all the latest fixes:
Update your Apple Watch
2. Unpair and erase your Apple Watch. Completing this step can help correct software related issues. (Before erasing all content and settings on your Apple Watch, your iPhone creates a new backup of your Apple Watch. You can use the backup to restore a new Apple Watch. )
If the issue persists, we suggest that you connect with Apple concerning this issue. They will be able to look further into this with you: Get Support
Best wishes.