Rekey what tile number? Not sure I know what you are trying to say...
Terrain != tileart in either client. In situations where tileart is available that matches terrain, it was copied using the terrain as reference at some point in the near or distant past. With the exception of transition tiles or variations within a terrain tile set, the position of the terrain tile on the underlying terrain geometry doesn't change the base terrain texture, only tries to add shadows to show depth and such. We'll have another look at the tiles to see if there is an issue. Thanks.