Make sure you display the TileMap bar, you'll need it (Menu/View/Bars/Tilemap Bar)
Once you add the tile map, use the tile map bar to load the Tiled map.
Remember to use Tile Map layers only in Tiled.
Remember to only use 1 tile set.
Add a tile map in Construct for each layer in your Tiled map.
Then you should be good to go.