What does the number of skulls on POIs mean exactly?

[lentil]

On a Tier 5 Quest, I was sent to the 'Pass-N-Gas Store #05' POI. This POI has a 4 skulls "rating". Up to then I believed that this "skull rating" matched the difficulty tier of the quests that would send you there (for example, the Shamway Factory POI is a Tier 5 Quest and has 5 skulls (5 red +2 orange skulls because it's in the Wasteland, to be precise)) and this is generally the case, but not here. Should I report this as a bug?

Edited August 14, 2023 by lentil (see edit history)

[Riamus]

26 minutes ago, lentil said:

On a Tier 5 Quest, I was sent to the 'Pass-N-Gas Store #05' POI. This POI has a 4 skulls "rating". Up to then I believed that this "skull rating" matched the difficulty tier of the quests that would send you there (for example, the Shamway Factory POI is a Tier 5 Quest and has 5 skulls (5 red +2 orange skulls because it's in the Wasteland, to be precise)) and this is generally the case, but not here. Should I report this as a bug?

Are you sure you weren't on an Infestation quest?  Infestation quests are done at a POI that is one tier lower than the quest. 

[lentil]

7 hours ago, Riamus said:

Are you sure you weren't on an Infestation quest?  Infestation quests are done at a POI that is one tier lower than the quest. 

That's exactly right. Thank you!

[Subasu]

On 8/14/2023 at 6:24 PM, lentil said:

On a Tier 5 Quest, I was sent to the 'Pass-N-Gas Store #05' POI. This POI has a 4 skulls "rating". Up to then I believed that this "skull rating" matched the difficulty tier of the quests that would send you there (for example, the Shamway Factory POI is a Tier 5 Quest and has 5 skulls (5 red +2 orange skulls because it's in the Wasteland, to be precise)) and this is generally the case, but not here. Should I report this as a bug?

Then you got a T5 infestation clear.  Which always drops you down 1 difficulty point.  So a T5 infestaTION CLEear will take you to a T4 location.