Note 9 Notifications Vibrates weak???

[Android Central Question]

So i own a Note 9 yes brand New! and i noticed that when I get a notification it vibrates weak?? but when i reboot the Phone the vibrate becomes normal then few idk hours or minutes it vibrates weak again....did i mess something up??? all i know is i had to factory rest cause one point the System UI stopped working and my phone was unusable so yeah don't know if that caused harm to my phone....