[Android]: TalkBack doesn't speak when AccessibilityEvent is triggered

Question

I'm creating a custom view (extending View class) and playing with Accessibility API to understand, how it works. Below is my code, where:

1. I check for MotionEvent equal to ACTION_HOVER_ENTER and then inside it send AccessibilityEvent of type TYPE_VIEW_HOVER_ENTER.
2. I'm catching my AccessibilityEvent in onPopulateAccessibilityEvent. Then I'm adding my custom text into event's text, which is added just fine.

As a result, when I hover over my view, all is working fine (confirmed by my logs), but TalkBack doesn't say my custom text. The only way I was able to make TalkBack to say custom text is to use setContentDescription("custom text...").

But, the way I understand the API, it should be possible to set different text depending on the type of MotionEvent and correspondingly a type of AccessibilityType.

My question - can someone explain to me please, how can I make TalkBack to speak my custom text, which I can set depending on type of event?

@Override
    public boolean onHoverEvent(MotionEvent event) {
        final int action = event.getAction();
        switch (action) {
            case MotionEvent.ACTION_HOVER_ENTER:
                Log.d("test", "onHoverEvent: ACTION_HOVER_ENTER"); // <-- this is triggered correctly on hover enter
                sendAccessibilityEvent(AccessibilityEvent.TYPE_VIEW_HOVER_ENTER);
                return true;
        }
        return super.onHoverEvent(event);
    }

    @Override
    public void onPopulateAccessibilityEvent(AccessibilityEvent event) {
        super.onPopulateAccessibilityEvent(event);
        if (event.getEventType() == AccessibilityEvent.TYPE_VIEW_HOVER_ENTER) {
            Log.d("test", "onPopulateAccessibilityEvent");
            CharSequence text = "this is a test";
            Log.d("test", "text before: " + event.getText()); // text before is empty, i.e. "[]"
            event.getText().add(text);
            Log.d("test", "text after: " + event.getText()); // text after is "[this is a test]", but TalkBack is silent
        }
    }