I have 214 desynth in LTW
On gyuki leather gloves of casting (item level 200), I'm getting 0% chance.

Gaganaskin belt of scouting (item level 255), getting 35% chance.

Gyuki leather shoes, i200, again 0%

Gaganaskin halfgloves i180 (!), only 28%

is something really bugged with desynth in SB or I'm missing something obvious?