it's not a bug, when NBLE is created through fusion it's tmp value is 1 instead of 0. tmp0 nble turns to sprk(plsm), while tmp1 nble turns into sprk(nble). you can prove this with the console command; "set tmp nble 0"
...you changed the tmp of the nble to 1. Regular nble doesn't do this. Sorry.
ive noticed this since the latest patch. it probably changed how it behaves.
I DONT KNOW WHAT IT IS BUT 1+