Definitely, if you don’t use an action to remove objects, that should not happen 
. Maybe the object has moved at the same position of another, looking like has been removed, try to check the number of objects and their position in the debugger: Debugger location
Tip: I can see every tile is located at same position, you could make something like:
Centre is not in collision with HexTile | Variable RandomTiles = Random(19)
| Create object HexTile at 0;0
| Position of TileHex = Centre.PointX(Centre);Centre.PointY(Centre)
| Z-Order of HexTile = 1
Variable RandomTiles <= 5 | Animation of HexTile = 1
5 < Variable RandomTiles >= 10 | Animation of HexTile = 2
10 < Variable RandomTiles >= 15 | Animation of HexTile = 3
. . .
Since the change of animation is placed in a sub-event, the newly created object remains as the reference object 
The events seems fine, I guess there is an event that changes the Centre object position to create tiles in other locations… Maybe the condition “!= Centre collides with HexTile” doesn’t work as you need and/or expect, I don’t know if the condition take in account the whole of HexTiles to launch its actions (It means “Centre is not in collision with any HexTile”, I guess it’s what you need), or if it’s sufficient that Centre doesn’t collide with someone HexTile (it means if you have two HexTile and Centre collides with one, there is some HexTile that doesn’t collide with Centre and the events launch its actions)
It should be possible with the child variables in the format: ParentVariable[“ChildVariable”], there is not other way to create variables “intelligently”/with a variable name, I think 
For example: PlayerPositions[“x”+VariableString(posX)+“_y”+VariableString(posY)+“_z”+VariableString(posZ)] = 1
The example should create the variable PlayerPositions.xa_yb_zc if it doesn’t exist (Variable posX = a, poY = b, posZ = c), you can check if a child variable exist too 
Finally, while I studying the Python basics read it many times and come to the conclusion that it’s very difficult, under-performance and probably there is a better way to do it, I recommend you try to find alternatives 