Since the rats drop wish ticket now, the dimension pass will then be pushed outside of the boundary and fall on other platform, which in turn making the stage that requires range attacker impossible to be completed. In the SS the dimension pass should fall on the box but not on the bottom platform and you can see that wish tickets have pushed it away and caused this to happen.
I tried this in the past but the coupon can't be looted. And even if you can loot it, if you want to drop it on the correct platform it requires someone who can flash jump or use wing + recoil effectively, which means it is rather impossible most of the time.
In addition to this, we just happen to have an Night Lord in our group and was she able to jump to the box/ticket. She couldn't loot the ticket nor hit the box with default attack. Removing the event drop would solve this bug and if possible add these reactor mobs (including the one mice at the boss stage) to a certain whitelist so they don't drop event items in the future. Thanks everyone for such a quick reply and fix. Happy mapling~