I have encountered a bug that causes all enemies of every wave to drop items such as tiles and portals as well as item packs that contain items. Interestingly, I received an incredibly low number of Green Papers for this game, which makes me assume that when an enemy drops an item, it does not drop Papers.

While I'm not entirely sure what caused the bug, I can go over what I did- I was on map 5.7 and completed the "Enemies Killed By Tower (Cannon)" quest when I put my phone to sleep, set it down, and got myself a glass of water. When I returned and turned the screen back on, this began occurring- It's worth noting I did not organically pause the game when I left. I have provided a few screenshots of it happening, in-game. I'm not entirely sure what is and isn't important in the context of the screenshots, so I tried to include as much information as I could.

As a programmer, what I suspect happened is that the game made an rng check to spawn an enemy with an item that wave and succeeded, but when the enemy that dropped the item (with a border) spawned, I turned my screen off precisely at that moment, causing it to somehow miss the trigger to turn off the item check. Why this would cause every enemy to drop one I'm not sure, though it could be a result of it making that check on the spawning of every enemy, which I think would be a little inefficient. However, I didn't make your game, and it's entirely possible that it's coded wholly differently.