sACN and DMX patch issue

I have an ETC Ion console in one of our rooms.  We were having issues with 1 of 8 moving lights we've had plugged in and wired since 2010.  The one we're having issues with is near the middle of the linked fixtures, not at the beginning or end of the series.  So looking at the patch screen, that fixture show a  " + "  in the sACN and DMX columns, not an asterisk like all the other ones.  It's the first time I've seen that.  Anybody know what that means?  I don't see it in the manual, or at least I haven't come upon it yet.  Thanks in advance!