Impossible: in the case of i use seamless mode, i must give a square value, i can't set separatly width and height.
I know for the period but still give me unexpected result.
The second image you see is a period of 64. The main tilemap is setup to 96x96 (x 8 chuncks as copy). I doubt increase the numbers of cells will change something.
There are the map i have with a texture from Gimp. Never i have this king of result, after all my tests.
@xyz what render have you got ?
![](https://i.imgur.com/2Up7405.jpg)