Nuendo 12 - Kontakt 6 multiple outputs Render in place doubt

Hi!, I need some help wit h Render in place and Kontakt (multiple outputs) , I’ve started to use my 5.1, I use orchestral libraries and I route Kontakt / Nuendo to work with different MICS (Stereo + Sur + LFE) everything works as expected, the problem appears when I render this Instrument track, sometimes I get only one wav file, sometimes I get the 2 o 3 outputs from kontakt (this is wat I want) I can’t understand why there are different results with the same kind of tracks … perhaps I’, missing something?