I searched for iron in the research bar and the game indicates me many tiles where supposedly there is iron.
However, as you can see there is not. In particular, the same thing happened on my territory, and I even destroyed what I had built on the tile (a farm) with the hope that I could make an iron mine later. But it didn't work.
Is that a bug?
You are searching for "Fer", and the game also found "Ferme". This is not a bug, but simply how the search feature works in this game.
Fortunately, you can tell the game to ignore "Ferme", so that it will only find "Fer" instead.
Take the following screenshot for example:
As you can see, I'm searching for "Stone", but I also found "Stonehenge".
But if I filter "Stonehenge" (see the red marking):
Then the game only searches for "Stone" while ignoring "Stonehenge".
You can do the same with "Fer" and "Ferme".
