Steps to reproduce:
1. Open ExtraTriggerExit project.
2. Open "MainScene" scene.
3. Go to play mode
--Notice that Console printed what objects and when they entered into "TriggerSphere" object
4. Now enable "Yellow Rigidbody" object which ignores collision with Blue Child Cube

Results: OnTriggerExit events, followed by OnTriggerEnter events, are reported for "Red Parent Cube" and both of its children (for objects that are inside trigger area).

Reproduced with: 5.3.4f1; 5.3.5f1; 5.4.0b19; 5.2.4f1