What kind of flame are you using? With the balls fusing, are they
attaching and then cracking off, (porous seam) or are they just not
sticking at all? Palladium is famous for absorbing excess gas, and
can be laser welded, but not easily fused. The content in your gold
alloy could be the problem. You might have to commit the cardinal
granulation sin of using solder. Or you could try the traditional
white gold alloy, which might work better for you for this project.
Or, would using traditional gold for the granulation work, say for a