I always hated this method of setting up mysteries. The author broke the sequence of events in order to hide information for some kind of "huge" reveal later on (most likely in the form of a half-assed flashback.) I don't find it a compelling mystery if the author just straight up refuses to share with the reader information that all the characters already know. Just screams bad writing imo. And it kind of killed a huge part of my investment in the story.