Every group will have a “problematic” or “flop” phase in their career these days (even new groups) because any group will get whatever accusations and everyone but superfans will believe them then use them against the group.
Or unless groups keep surpassing their own record every CB, they will get labeled flops, and eventually, everyone will find them lame. Sadly I think this is the current reality of Kpop. Groups have a short expiry date.
It’s the age of the combination of canceling and achievements’ obsession.
Usually, I would say ignoring the haters will do the trick because even in the past those things probably existed. However, unfortunately now these people’s comments are heard by the agencies because they come in huge numbers (the expand in social media's reach) so they reach the artists more than before.