I'm guessing you have a problem with your tool definition. I suggest copying the 1/8" taper definition and change it to fit your own tool. That would probably fix it. There's really no difference between a 1/16" ballnose and a taper except the strength of the bit and the diameter of the shank. The way you have the tool defined looks like it would be wacko. Which is probably why you see lines. It's a 1/4" diameter tool to the database. At least that's the way I see it.
ShopBot Details:
2013 PRS 96x60x12 (Centroid upgrade)
4hp Spindle
12" indexer
Aspire
Rhino
Fusion 360
Ferrari 360
Prusa MK3S+
Prusa XL multi-tool