FIrst, if using a v4.x My Cloud, update to the latest firmware released yesterday. It may fix the USB drive name issue.
Second, its a well known and discussed issue that can be found by doing a subforum search using the magnifying glass icon upper right. The workaround for the previous firmware version(s) was to remove/eject the USB hard drive using the My Cloud Dashboard, then access the Shares page within the Dashboard and remove/delete all instances of the USB drive name. Then reattach the USB hard drive to the My Cloud, and while still on the Dashboard Shares page select the USB drive name and rename the Share back to the original USB drive name.
Here are just a few past threads on this issue:
https://community.wd.com/t/my-safepoints-disappear/160698
https://community.wd.com/t/new-release-firmware-release-04-04-02-105-1-27-2016/148441/68
https://community.wd.com/t/mycloud-creating-numerous-aliases-for-same-drive/160161
https://community.wd.com/t/usb-drive-makes-new-name/152675
https://community.wd.com/t/dublicate-shares-after-reboot/153348
