well first look at them. they were still very very popular, but to answer your question think of what happened. le sserafim literally before they were announced has a rumor stirring. The garam rumor. Now at the time, yeah it wasn't big because no one new the members or if she was even really going to debut. Then it happened and the scandal went out of proportion. It is a bullying rumor too, which for koreans they dont take lightly, then weather false or real it started to backfire on the other members as they also got those same claims to a very small degree compared to garam. They are also under Source Music which is popular but doesn't have the best reputation in their girl group management and very prevalent favoritism in some of their old groups. Which did not help the group at all as a more reputable in management sublabel mite have made the gp less scared or angry about how the sandal will be held and would result in a slightly more muffled response. (Think bight responding to allegations against bts, they handle it ok). It was just a cocktail of bad that i want you to see that had mostly to do with the gp's perception of the actual members personality, real or not.
Now new jeans. Yes they did have a scandal but the sandal was more about the people who made them not the actual members personality, which dose make a difference and leads to people wanting to protect them more from who made them rather than split them. It also builds a small fanbase that protects the girls and talks about them (kind of like bad press was good press for them). Also they came from a newly developed sublabel which helped! A LOT! The label had no other sandals that would lead the gp to think they are untrustworthy and also they made the gp curious as to what the gg's sound would be and the visual criteria. Overall even though they had a sandal it couldnt be used too much against the members which leads to better gp reception.
Hope this helps!
