Consistent positive response to the characters tells me you’ve developed your character arcs well, so the events in the plot are probably well chosen and executed, and your characterization must be strong to engender such loyalty. I suspect your storytelling is heavy on dialogue and action but lacks depth that makes readers feel fully satisfied when they reach “The End.” It’s the difference between a sweet dessert and a rich one—both are yummy, but only the latter has you walking away from the table feeling full. You can enrich your story by doing a world-building revision pass. I don’t mean dropping in a bunch of setting descriptions to slow the reading. Rather, work in setting details with language that conveys an atmosphere, have the characters act upon and react to props unique to the spirit of that place, and include smells and textures that engage readers’ senses. This enriches the reading experience, making it feel full instead of breezy.