Unfortunately, the issue still persists even after the latest update. When trying to leave the bestiary (regardless from which discovered or undiscovered entry), no matter on which map, the screen gets stuck in an endless "Now Loading..." animation (no error message, just a loading loop). As I said, this only happens after I've entered Cradalios Canyon for the first time, but the loading loop occurs on every map, not only in Cradalios Canyon. If it helps, you can tell me your e-mail address so that I can send you my latest save file. I guess I'll use the bestiary less frequently at least for a while. :D
Good news! I found the problem through playtesting the game up to that point! If you encounter a enemy for the first time in Cradalios Canyon, THIS is the trigger, because the background is not one of the default ones that came with rpg maker mv im guessing? (VERY WEIRD) I'm going to see if I can fix this because I really enjoy the Cradalios Canyon background haha
Thanks, the issue seems to be fixed. I loaded a save file from before entering Cradalios Canyon, and after the first encounter in Cradalios Canyon, the bestiary still works as intended. Unfortunately, my latest save file still suffers from the loading loop, which means only new players won't encounter this issue. Instead of letting you fix my save file (if that was even possible), I'll sacrifice one hour of progress and resume my playthrough from the latest unaffected save file (honestly, it's my own fault for not stopping immediately after discovering that bug). It's still better than practically not being able to use the bestiary.