Rob, I ordered a few new XS carriers and a Cell notecards.
Seems its not limited to the Wifi card. Running a WB Notecard with a Starnote it still browning often.
Mon 02:45:33 PM: boot (brown-out & hard reset [17494])
Mon 05:33:41 AM: boot (brown-out & hard reset [17494])
Mon 03:13:36 AM: boot (brown-out & hard reset [17494])
Mon 02:57:32 AM: boot (brown-out & hard reset [17494])
Mon 02:56:49 AM: boot (brown-out & hard reset [17494])
Mon 02:40:38 AM: boot (brown-out & hard reset [17494])
Mon 02:39:12 AM: boot (brown-out & hard reset [17494])
Mon 02:08:24 AM: boot (brown-out & hard reset [17494])
Mon 01:53:03 AM: boot (brown-out & hard reset [17494])
Mon 01:37:39 AM: boot (brown-out & hard reset [17494])
Mon 01:22:17 AM: boot (brown-out & hard reset [17494])
Mon 12:51:58 AM: boot (brown-out & hard reset [17494])
Mon 12:36:38 AM: boot (brown-out & hard reset [17494])
Mon 12:21:14 AM: boot (brown-out & hard reset [17494])
Mon 12:05:45 AM: boot (brown-out & hard reset [17494])
Sun 11:50:19 PM: boot (brown-out & hard reset [17494])
Sun 11:34:55 PM: boot (brown-out & hard reset [17494])
Sun 11:19:15 PM: boot (brown-out & hard reset [17494])
Sun 10:18:48 AM: boot (brown-out & hard reset [17494])
Sun 09:28:53 AM: boot (brown-out & hard reset [17494])
Cellular only seems ok.
I updated everything to latest firmware 11.1.1.17494.
The units that are giving me grief are older frimware I beleive . Will confirm shortly