Hi viki205, thank you for posting in Apple Support Communities. We understand that you're no longer receiving notifications for a specific app on your iPhone, but the notifications do appear on your Apple Watch. Does this seem to only happen when your iPhone is locked or asleep? If so, this is an expected behavior. For more information, please check out: Notifications on your Apple Watch - Apple Support
If the issue occurs whether or not your iPhone is locked or asleep, we ask that you check out the "If you don't see notifications for a specific app" section of the following resource: Use notifications on your iPhone, iPad, and iPod touch - Apple Support
Let us know if that helps.
Cheers!