You are overlapping the sprite images. So when you click on outsides(non overlapped parts) they work as intended, but if you click on any overlap they will not work. This is what we meant when we said, you can't see it but it is still there. Invisible sprites are clickable.
You need to mark sprite 7 as invisible either in properties or on start of layout like you did sprite 4.
But you can't overlap the sprite buttons because you will be pressing both.
Swapping image frames returns true permently once button pushed. You click sprite3 image - frame is 0 and it turns to 1 and stays there because you click it and it runs through cycle because it is then true that animation frame is = 1 and so forth. so it doesn't move from animation frame 0.
True is true that is why we used the else because it puts a block that if condition 1 is true then do this else do that.
Destroying objects And changing positions
Could be a bug? Can't put my finger on it off hand and limited time.
You have two example capx from yesterday. Easiest way and it works. If you want invisible - then make 2nd image frame clear.