I'm curious. At what point in your novel do you drop hints about the flaws of your world, the "dark side" of your kingdom? I've had a reader tell me the larger problems in the world (poverty, illness, corruption, etc.) should be presented within the first few chapters.
snow,
be leery of something that general.
1. were these betas who saw your work? I have several betas, some of whom I have zero doubts are better writers, as well as just plain smarter than me.....and I tend to listen to them, but even they, on occasion, are formula-bound. Or biased. But if a beta saw, they MAY be saying when you get to conflict it comes out of nowhere, and therefore feels forced and artificial...."shit suddenly happens...er, because it HAS TO so we can get to the drama...."
2. If not, are they just offering very general views of story structure in general?
as a very general rule, there should be some sense things are off, even if the MC is unaware. In fact, if you're really good, and the MC is unaware, the reader won't even see the breadcrumbs for what they are until AFTER the MC finally does, sort of like all the little tells in The Sixth Sense about the estranged wife, etc.
That said, so long as it isn't an issue of snowflakery, your story trumps this very soft "rule", imho. If you have a valid reason they'd be unaware and you stick tight to their POV there may be no actual hints or suggestions to mention until they also realize what is wrong. At the same time, if they are aware now, and wrongness permeates their world, it should be shown. Even horrible things can be mentioned in passing, as part of just...mundane narration, I guess....
"Cotton hated Wednesdays; he'd have to get up extra early for work, stop at the ration line afterwards, and the worst part would be the fucking smell of burned kids sticking to his coveralls. It made for an exhausting day."
obviously you would get that something is wrong, and also, that it really isn't, so much, to the MC. For them, it is part of life. But in subtler cases, you just might not have anything to really say about the world right away.