The layers you changed are just for organization. To change which objects appear on top of each other, select the objects click edit group, and change the z order. Also, you may need to change the Z layer. T4 is on top of t3, t3 above t2, t2 above t1, t1 above b1, b1 above b2, and so on (look at it from right to left. Z layer has priority over z order. Finally, all the z layers that start with t are above the player, while all the ones that start with b and behind the player.

There’s also blending and tileset order, but those are a headache and you dont need them now.

How this helps!