How do I limit the size of a tile image

Hey guys, I created a few tiles as different objects to be able to create a few hidden places in my map. But the thing is, even though the tile size is 64x64 px and the image on it is also 64x64, construct2 sets a copy of the tile underneath it.

So when I try to test the game I get this weird green line appearing in the middle of the ground shown up exactly what I'm trying to hide.

I don't know what to do here, but this is really making my game extremely ugly.

What do you think?

So is each tile a sprite instead of using a tilemap?

It's not a bug, it's a feature.

Your game is so smart that even without additional code, she is trying to help players find all secrets, that you so desperately trying to hide from them.

No, I have a tile map. Only this two tiles on the picture are independent tile map objects

Well, I don't know how to solve this problem exactly yet. But I manage to change a few things and made the green line disappear and now the game is ok.

Thank you guys anyway ^^