Board Game Arena

Hi
On the standard map, when I place a tile on a “special” base, it says that I can retrieve a tile (normally anywhere on the board). However, when I try to do so, I am unable to retrieve a tile that is already covered by another tile.
Is this normal?
Best

I would like to play this game but the old version is way too ugly... (even if the game seems terrific). The new version would be so nice!!!