Why my phone stop vibrating while all settings are on?

@worzleft culd be the actual vibrator motor. First start your phone is Safe Mode and see if it works in that mode:

First, press and hold the Side button and the Volume down button at the same time. You can also swipe down from the top of the screen using two fingers, and then tap the Power icon.

Touch and hold the Power off icon.

Tap the Safe mode icon.

Safe mode displayed on a Galaxy phone

Once you're in Safe mode, you can remove the third-party app that is causing issues. Start by removing apps that were updated or installed when the problem started.

To exit Safe mode, simply restart your phone or tablet and it will reboot normally. Or, you can tap the Safe mode notification; swipe down from the top of the screen, and then tap the Safe mode is on notification. Tap Turn off. from here

If that also does not work try to dial *#0842# to test the vibration motor. If it has failed you may need to replace it. Since iFixit does not yet have a guide for that, use teh one from here It is in spanish but your browser should have no issue translating it.

While you work on your phone, take lots of pictures. Once you are done with it, take those pictures and create a guide for iFixit. That will help the next person that has the same problem as you do. It's easy and fun to create these guides. https://ifixit.com/Guide/new The iFixit community will appreciate this.