I had this issue last night. I used 100 pixel strings (so 50 up, then 50 down) and everything looked funky on the actual tree but Xlights showed it perfectly fine.
I have 16 strands (800 pixels total) This says you have 800 pixels
In Xlights this is what I had to set:
Type: Round
Degrees: 180
Rotation: 3 (don't know why)
Spiral Wraps: 0
Bottom/Top Ratio: 6
Perspective: 2
# Strings: 16
Nodes/String: 100 This says you have 1600 pixels
Strands/String: 2
Starting Location: Bottom Right
See red above how many pixels do you have?
Yes, I do. I guess I didn't really think about the calculation. I changed it to 50 and it still worked perfectly. Thanks for catching that for me!