faders

My X32 is not responding to certain commands for setting fader levels. If I send /auxin/01/mix/fader ,f .2 the fader moves up .2 fine. If I send /auxin/01/mix/fader ,f .5, it goes halfway up. So far so good. However, sending ...,f .3 or ...,f .4, or anything greater than .2 and less than .5, the...