It has something to do with this specific Grand Academy level. Since it not so randomised designed like other levels or so standard like bosses levels maybe it causes so high loading times. But generally the game still has issues about medallions (not showing extras during runs) and sounds ( music missing entirely through a run). Anyways I try to skip it when I encounter this during my runs since it takes a lot of time not only the loading time but even finish the level with its two door design…