The Bug:

I summoned a drowned on surface and it was not attacking me at all, and just disregarded my existence.

How to reproduce:

1) Open a world

2) Go to survival

3) use /summon drowned command or give yourself a drowned spawn egg

4) Watch as the drowned just doesn't acknowledge that you exist

Observed Behavior:

The drowned ignores the player 

Expected Behavior:

The drowned would not ignore the player and will attack it in attempt of killing them

Demonstration videos:

Video 1

Video 2