I have a world map I am trying to import into FTpro. The world is set up in CC3 as 25000 miles in circumference, 12500miles north to south. I exported the map as a greyscale bitmap at 4096x2048 (later as 5000x2500 pixels as well). After converting the map in Wilbur to a .dte file and loading it into FTpro (as per Ralf's tutorial) I get this odd seam at the 180/-180 degree edge which runs the entire height of the map north to south. The seam is hidden until I spin the globe to show that hemisphere, but once the -180/180 edge is near the center of the view, there it is.

I have tried checking the horizontal wrapping box when importing the height map, messing with the map edge settings, changing the resolution of the bitmap to better match a multiple of 360degrees, and changing the world circumference to better match a multiple of 360degrees. I have noticed that only one edge goes to +/-180 while the other approaches it, but is only +/-179.xx before looping over.

What is causing this artifact and how can I get rid of it?