Try this: [Login to see the link]
This app can silence your contacts. I haven't tested it out much, I don't know if it will fix your vibration issue, let me know once you try.
Unfortunately, there are prerequisites. This app uses a few permissions, like contacts and calling. It also needs do not disturb access].
I was able to setup that permissions via [Login to see the link], but on a phone with the regular settings app, the Mute Contacts app just crashes. I think there is an ADB Command to allow it, (probably one that start with adb shell appops set), but I couldn't figure it out. It's possible that there is an app that can allow those permissions, I'll look into that.
Note: If you decide to install [Login to see the link], do it via ADB, the instructions in the linked post don't work for many people.
Also note: When you open the app, there is a very annoying, useless introduction. There is a skip button, which doesn't work 🙁. So, you'll have to sit there for two minutes and watch it.
