I think the reason why they underperformed this era
was simply the music.
For the first single they used an intro from their ILY comeback stage
then the second single was practically something from the To Anyone era.
I think an important quality that 2NE1 has is that they make music relatable to the GP
Lonely, Go Away and UGLY are examples of that.
They didn't have that this era, if we compare it to the 2nd Mini era they had an amazing start with Lonely.