Hey della120,
It appears that you're not hearing a notification sound on your iPhone or Apple Watch when you receive a text in the Messages app, and we're glad to provide assistance.
Use Focus on your iPhone, iPad, or iPod touch - Apple Support -- If you've created a Focus on your iPhone, make sure that the Messages app is allowed to notify you. If you're also sharing the Focus across devices, this could be the reason you're also not hearing a notification sound from your Apple Watch as well.
Use notifications on your iPhone, iPad, and iPod touch - Apple Support -- If you aren't using a Focus, go to Settings > Notifications > Messages. Scroll doing to Sounds. Tap the sound you've selected to make sure it plays. If it does, scroll back to the top of the screen and turn off "Allow Notifications", then Restart your iPhone - Apple Support. Once your iPhone is back at the Home screen, go back to Settings > Messages and turn Allow Notifications back on and test the issue.
Notifications on your Apple Watch - Apple Support -- Also, check the notification settings for the Messages app on your Apple Watch as well.
Please let us know the results when you're able by replying to this post.
All the best.