Question about darkness, faerie fire, and blinded (re: (dis)advantage)

So, I got confused by a rules question.  And I don't agree with the explanation I was given at table, based on the RAW.

Disadvantage/Advantage don't stack and they cancel each other out, correct?  So, if 2 sources of disadvantage apply, and 1 source of advantage applies...is it correct to say that the roll is normal, and not at disadvantage?

Scenario: Magical darkness as an aura, but the creature is hit with an upcasted Faerie Fire at 3rd level.  But if you failed the constitution save for this darkness (some special Shar variant), your character gains the blinded condition.  So blinded and darkness both give disadvantage, neither stacking.  And the target has Faerie Fire (which, due to be upcast is not dispelled by the darkness), which gives advantage.  So disadvantage and advantage cancel out and, even blinded, the roll is a 'normal' roll, correct?

As described in the Player’s Handbook, if different circumstances would give both Advantage and Disadvantage in the same situation, the Advantage and Disadvantage cancel out, regardless of how many circumstances would grant Advantage or Disadvantage.

Is my understanding correct here?  I was told that the darkness effect cancelled the advantage from Faerie Fire, but that Blindness would apply disadvantage.  That doesn't appear consistent with the explanation above.  Did they misunderstand this rule, or am I missing something here?  If I'm missing something please advise.

The rules for Advantage/Disadvantage are straightforward in that they cancel each other and the roll has neither of them, so if handled differently, i'd say it's either misremembered or houseruled somehow.

Specifically with Faerie Fire, there's a requirement that you be able to see it to get the advantage. If you're blinded, you can't see it.

The explanation may have been confused, but the result seems correct.

Quote from jl8e >>

Specifically with Faerie Fire, there's a requirement that you be able to see it to get the advantage. If you're blinded, you can't see it.

The explanation may have been confused, but the result seems correct.

That's a very good point. Not being able to see the creatures affected by Faerie Fire would mean the advantage didn't exist at all, not that it was canceled out by disadvantage.

Quote from jl8e >>

Specifically with Faerie Fire, there's a requirement that you be able to see it to get the advantage. If you're blinded, you can't see it.

The explanation may have been confused, but the result seems correct.

 The description was that it was visible through the darkness as a light in the middle of it.  And, when asking about the nature of the blindness, it was described as "blurry blindness", not completely "blackout" blindness.  In which case I would think the cancellation effect would still be in place.