96 Khz rate on x1850

Hi , anybody know’s why the quantize are not available as well as some FX in this rate ? All the files that i play are in AIFF I’m on the 1.2 Firmware and my two SC6000M are connected in DIGITAL to the mixer . I also have the volume who goes up and down by itself for a few minutes when i turned on the mixer( in all rates this time 44.1 , 48 and 96 ) . Thank’s