1. The text compare is case sensitive. You have Move = "Left" but your event checks for Move = "left".
2. You should use an invisible sprite for the platform behavior or the enemies will likely go through the EdgeMarker... (https://www.scirra.com/tutorials/253/how-to-make-a-platform-game/page-4)
3. Don't use solid behavior on the enemies or they'll block each other.
4. The enemies have been destroyed before it gets to the loot spawning events. Use the 'on destroyed' condition to spawn the loot when an enemy is destroyed.
5. Use floor(random(1,3)) instead of round(random(1,3)).
floor(random(1,3)) = 50% chance of 1, 50% chance of 2
round(random(1,3)) = 25% chance of 1, 50% chance of 2, 25% chance of 3