Christmas present: brand new EX2 Ultra WDBVBZ0080JCH-NESN.
It is plugged via USB directly into the central hub of my Ubiquiti AmpliFi HD WiFi.
Shows up on the network as expected, and a Share will readily mount on any of multiple Macs (both desktops and laptops) all running MacOS 10.14.2 Mojave.
If I mount the Share volume and copy a small folder (say 100 MB or less) it will copy just fine.
If I try to copy a larger folder, a few hundred items say 500 MB or more, it will start copying for a couple minutes then the Mac will freeze entirely and then reboot. I confirmed this on multiple Macs and got the same behavior on similar conditions.
I tried reformatting the EX2 from a RAID 1 to a JBOD to see if that had any impact - problem persists.
I tried disabling Oplocks for the target Share (what the hell) but that had no impact either.
Any ideas? Some update? Does EX2 not work with MacOS?