I now have an external 2-Bay USB 3.0 enclosure (ICY BOX IB-3620U3) plugged as an extension of my MyCloud EX2 but get only one single device instead of two individual discs shown! The box works as JBOD / single with no configuration options. Plugged on the Mac directly it appears as intended and expected both disks as separate volumes. They appear at the Mac clearly the one as “Disk A” and the second as “Disk B”. The disks are formatted HFS + but a trial formating as FAT32 also brought no other result.
Plugged into the USB port of the MyCloud EX2 only a single USB device as “ICY_BOX_IB-3620U3” appears but none of the named partition (s)! When you write always the first disc is used at the MyCloud EX2 apparently, the second disc is ignored. Why is this so? I have not named one A and one B for no reason and will actually use BOTH for several different backups!