Thanks for that info and choosing the Apple Support Communities. Based on what you stated, it seems you are experiencing issues with not having your iPhone X vibrate with notifications for the Messages app. To help with this, please go to Settings > Sounds & Haptics and toggle the "Vibrate on Ring" setting from Off to On. Next go to Settings > General > Accessibility > Vibration and toggle the setting from Off to On. Now restart your iPhone as iOS clears cached data and does other system optimizations when you turn your device off and on.
Restart your iPhone, iPad, or iPod touch
If you're still having this issue, please make sure your iPhone is up to date, as the updates contain stability fixes that can resolve issues like yours, as well as important security updates to keep your iPhone safe.
Update the iOS software on your iPhone, iPad, or iPod touch
If you have competed these steps and you are still having this issue, please make sure to make a backup of your personal data and settings, and then reset all settings on your iPhone by going to Settings > General > Reset and choosing the Reset All Settings option.