ION arrows on wing

Are the submasters assigned to those faders, also assigned to faders on a different page? I'll think you'll find that those other faders are above 0%, and so the faders on your page are telling you that the sub is at a higher level elsewhere.
I'm guessing your subs are currently empty... otherwise you'd also see the light on the bump button flashing.

I still need to do some checking however as I know so far it appears those up arrows and windows with no windows never change on any cue running, even when GTC Out has been initiated and nothing is running and when no assigned subs are up. I have 60 faders on two wings; 40 on one and 20 on another. I have less than 20 subs assigned to them on only one wing (the 20 fader wing) and even when all of them are off or down those same remaining faders show the up arrow on each one except for those same few that have nothing showing. They only appear on the wing with the 40 faders. There are no arrows on the 20 fader wing. I realize most of them are assigned subs and show those assignments however those that don't have anything assigned just show a blank window above the fader. It looks like it seems to be specific to that wing, maybe just because it's on page 1 showing 1-60.
What exactly are those arrows? The are certainly new to the newest software.

The idea of the arrows is this: because the faders of the universal fader wing are not motorized and you can control subs also by command line, there are moments when the physical handle of a fader can be at a different level than the internal (actual) value of the sub. So if some stuff is out of sync, the arrow shows you in which direction to move the handle to make the actual and virtual values match again.