Lost connection to stagebox

Hi everyone,

last weekend i had a bad isssue with my console…

First of all this is my setup i use very often:
SQ6 - foh
AR2412
AB168

The first day we had a rehearsal and everything worked great. i connected the AR2412 via Slink to the console and the expander from the stagebox to the AB168. Fine.
Next day, showday, i booted up all the system - BUT the AB168 wasn’t found ? i tried a lot of different things but the problem was there.

I needed 40 inputs and it wall really bad that i couldn’t handle it. A half our before the concert i restarted the system again and then it worked surprisely.

What was my mistake i made?

Thank for your help