Could not find custom method in androidx.appcompat.widget.TintContextWrapper for onClick handler in MaterialButton

I have recently ported my app to material design and I have started to receive weird errors suggesting that methods are not found in activity (while they are and where there for last 3 years or so) and everything ends in crash for user. This seems to happen only to users that are running Android 4.* (4.0.2, 4.2, 4.4), various devices (Samsung and LG), any suggestions how to address it are appreciated! :)

Full error message:

Fatal Exception: java.lang.IllegalStateException Could not find a method onCancelClicked(View) in the activity class androidx.appcompat.widget.TintContextWrapper for onClick handler on view class com.google.android.material.button.MaterialButton with id 'btnCancel'

(...)

Caused by java.lang.NoSuchMethodException onCancelClicked [class android.view.View]

parts in italic are custom methods, see below for the layout

    <com.google.android.material.button.MaterialButton
        style="@style/Widget.MaterialComponents.Button.TextButton"
        android:id="@+id/btnCancel"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:onClick="onCancelClicked"
        android:text="@string/dialog_conf_code_cancel" />

Activity handling this layout implements AppCompatActivity, while the onCancelClicked is simple, as below:

public void onCancelClicked(View v) {
    this.finish();
}

I also get similar errors for other buttons implemented in this way, again - so far only for some users with Android 4.*.

My dependencies in build.gradle are defined as below

dependencies {
    implementation 'com.google.android.material:material:1.0.0'
    androidTestImplementation 'androidx.test:runner:1.1.0'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.1.0'
    implementation 'com.google.android.gms:play-services-ads:16.0.0'
    implementation fileTree(include: ['*.jar'], dir: 'libs')
    implementation 'com.google.firebase:firebase-core:16.0.5'
    implementation 'com.crashlytics.sdk.android:crashlytics:2.9.6'
    implementation 'com.android.support:appcompat-v7:28.2.0'
    implementation 'com.android.support:design:28.2.0'
}

Again - any suggestions are appreciated! :)