Can the third benefit of the Mobile feat prevent multiple creatures you attack in a single turn from making opportunity attacks against you that turn?

Question

I am playing a monk. I wanted to use the Mobile feat, specifically the third option that prevents opportunity attacks, to do the following:

1. hit creature 1 with my attack, then move away from creature 1
2. then use Flurry of Blows on creature 2, then move away
3. then make an unarmed strike on creature 3

...all without provoking opportunity attacks from any of them, thanks to the Mobile feat.

However, I was told that I can not do that because it only works for one creature and only my action is a "melee attack" or some such reason.

Is my interpretation right according to "rules as written", or am I misunderstanding how it works? It seems quite vague.

Answer 1

The third benefit of the Mobile feat is limited only by the number of attacks you can make in a turn.

The third bullet point of the Mobile feat says (PHB, p. 168):

When you make a melee attack against a creature, you don't provoke opportunity attacks from that creature for the rest of the turn, whether you hit or not.

So when you make an attack against a creature, that creature cannot make an opportunity attack against this for the rest of the turn.

Notably, there is no limit to the number of creatures this can affect, except for the number of attacks you can make.

Suppose you are a 5th-level monk who attacks twice when they take the Attack action (thanks to Extra Attack, a 5th-level monk feature). If you make two attacks with your Attack action against two different creatures, and you spend a ki point to use Flurry of Blows to make two more attacks against two more creatures - that would be four creatures who would be unable to make opportunity attacks against you for the rest of that turn. For further clarity, it may be helpful to review this answer concerning the difference between an attack and an attack action.