Isn’t that aggravating? My devices would do the same thing, I came up with a fix that should work. It’s not hard, but takes a bit of time.
The problem is almost certainly with netbios in Windows. You can verify this by opening a command prompt and typing in 'Net View". If you get an error message then netbios is borked.
Open file manager and double click the My Cloud icon in Storage, this will open the admin page on the device. Go to settings, and network. Make note of the value of IPv4 IP Address, you’ll need that later. Scroll down and look for Windows Services. Make sure that Workgroup is set as WORKGROUP (all caps!). Right below it it should have a setting for Local Master Browser, make sure it’s ON. If you’re using windows 10 then SMB should be set for SMB 3.
I’m unsure if the My Cloud restarts services on a settings change, so to be sure, go to settings, Utilities, and look for the button to reboot the system.
(A couple of notes for others who may try this - if you have more than one My Cloud device, Local Master Browser should be set ON for only one device, others must be OFF. If you have an older unit, there may not be a setting for Local Master Browser. The only workaround is to SSH to the device and edit /etc/samba/smb.com and add/modify the following lines:
[global]
name resolve order = wins lmhosts hosts bcast
wins support = yes
local master = yes
os level = 65
preferred master = yes
domain master = yes
Only try this if you’re comfortable in Linux. I’m sure it voids your warranty, risks bricking the device, etc)
Next, go to each windows computer in the workgroup. From a command line type ‘net config workstation’. Make sure the Workstation Domain is ‘WORKGROUP’. From that same window, type regedit. Look for HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\ Services\Browser\Parameters in the tree. With Parameters highlighted in the tree, right click and New, String Value with a name of ‘IsDomainMaster’ and a value of ‘False’. Close regedit and command window.
Open Network and Sharing Center in control panel, click change adapter settings, right click on whichever you use ( Ethernet or WiFi), and select Properties. Click on Internet Protocol Version 4, and click on the Properties button. Click on Advanced, and then the WINS tab. Click Add to add a WINS server address. Put in the IP of the MyCloud that you noted earlier, and hit Add. NetBIOS should be set for Enable NetBIOS over TCP/IP.
Reboot the machine, and repeat the procedure for all other windows machines on the network.
You can test by opening file manger and looking in Network. The list of computers and devices should appear instantly. You shouldn’t ever see that problem again.