Unresolved reference databinding - Android Studio 4.0

I keep getting errors: "Unresolved reference: databinding" and "Unresolved reference: ActivityMainBinding".
I am using Android Studio 4.0, Android Gradle Plugin Version: 4.0.0 and Gradle Version 6.1.1.

build.gradle (Module: app):

apply plugin: 'com.android.application'
apply plugin: 'kotlin-android'
apply plugin: 'kotlin-android-extensions'
apply plugin: 'kotlin-kapt'

android {
    compileSdkVersion 29
    buildToolsVersion "29.0.3"

    defaultConfig {
        applicationId "com.example.twowaydatabinding"
        minSdkVersion 24
        targetSdkVersion 29
        versionCode 1
        versionName "1.0"

        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
    }

    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }

    buildFeatures {
        dataBinding = true
        viewBinding = true
    }
}

dependencies {
    def lifecycle_version = "2.2.0"

    implementation fileTree(dir: "libs", include: ["*.jar"])
    implementation "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"
    implementation 'androidx.core:core-ktx:1.3.0'
    implementation 'androidx.appcompat:appcompat:1.1.0'
    implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'androidx.test.ext:junit:1.1.1'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'

    // ViewModel
    implementation "androidx.lifecycle:lifecycle-viewmodel:$lifecycle_version"
    // LiveData
    implementation "androidx.lifecycle:lifecycle-livedata:$lifecycle_version"
}

build.gradle (Project):

buildscript {
    ext.kotlin_version = "1.3.72"
    repositories {
        google()
        jcenter()
    }
    dependencies {
        classpath "com.android.tools.build:gradle:4.0.0"
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
    }
}

allprojects {
    repositories {
        google()
        jcenter()
    }
}

task clean(type: Delete) {
    delete rootProject.buildDir
}

activity_main.xml:

<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools">

    <data>
        <variable
            name="viewModel"
            type="com.example.twowaydatabinding.MainActivityViewModel" />
    </data>

    <androidx.constraintlayout.widget.ConstraintLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:context=".MainActivity">
        <!-- layout content -->
    </androidx.constraintlayout.widget.ConstraintLayout>
</layout>

MainActivity.kt:

package com.example.twowaydatabinding

import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import androidx.databinding.DataBindingUtil
import androidx.lifecycle.ViewModelProvider
import com.example.twowaydatabinding.databinding.ActivityMainBinding

class MainActivity : AppCompatActivity() {

    private lateinit var binding: ActivityMainBinding
    private lateinit var viewModel : MainActivityViewModel

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        binding = DataBindingUtil.setContentView(this,R.layout.activity_main)
        viewModel = ViewModelProvider(this).get(MainActivityViewModel::class.java)
        binding.viewModel = viewModel
        binding.lifecycleOwner = this
    }
}

MainActivityViewModel.xml:

package com.example.twowaydatabinding

import androidx.databinding.Bindable
import androidx.databinding.Observable
import androidx.lifecycle.MutableLiveData
import androidx.lifecycle.ViewModel

class MainActivityViewModel : ViewModel(), Observable {

    @Bindable
    val userName = MutableLiveData<String>()

    init {
        userName.value = "Frank"
    }

    override fun removeOnPropertyChangedCallback(callback: Observable.OnPropertyChangedCallback?) {
        TODO("Not yet implemented")
    }

    override fun addOnPropertyChangedCallback(callback: Observable.OnPropertyChangedCallback?) {
        TODO("Not yet implemented")
    }
}

I tried:

• Build -> Clean Project, then Build -> Rebuild Project
• File -> Invalidate Caches / Restart

but nothing helps. Class ActivityMainBinding is never generting.
When I go to declaration of import com.example.twowaydatabinding.databinding.ActivityMainBinding in MainActivity.kt it redirects me to activity_main.xml. Code doesn't show any errors, but when I try to build the project those databinding errors shows up.
What am I doing wrong?