Hello - I have two EX2 Ultras in two different locations. My iPhone and iPad MyCloud iOS app sees both devices. When I login to mycloud.com - only one is online and the other appears offline (ironically the one in my same location on my desk).
They are both up and running. I can access them both via the iOS apps, as well as locally via web browsers.
I have tried rebooting the device and the router, I have turned off and re-enable cloud access - all to no avail.
This was all working fine / both accessible via MyCloud the last time I went to MyCloud a few weeks ago.