Iphone 14, current version of the live game at the moment of writing this message.
I guess that’s an upgrade from a few weeks ago or not where each time I would finish a zone, the game would crash and be unusable for several days. This time around, I just beat the last boss of Winterspring on Heroic (defeating all of them with multiple heroes). I think I got the money reward (didn’t pay attention) but as the book opened for the last reward, it instantly closed and I didn’t get the XP rewards. This also unlocked the 145th reward (an other big XP book) which just poofed when clicked on, once again, wasting the XP reward away.