Cannot access MyCloud drive from the Internet – Intermittent

I cannot access the MyCloud drives (e.g. EX2-Ultra and MyBooklive) via the Internet quite often but no problems via WiFi. This intermittent access problem applies to BOTH Windows 10 PCs (Chrome browser) and MyCloud app on iPhones. A few hours later or the next day the problems are no longer there and everything is working fine.

The error message displayed from the MyCloud app on the iPhone is “Remote access disabled. Access to xxxxxx (MyCloud device name) has been disabled”
OR the message “Drive offline xxxxxx (MYCloud device name) is not accessible. Local documents are available.”

We used MyCloud drives both at the office and at home and they all have the same intermittent access problems via the Internet.

I would like to know what is the cause of this problem?
(MyCloud EX2-Ultra Serial# WUBM38361647 Firmware 2.31.204)
p.s. I tried to ask the above questions via the WDC Support Contact page but it was not available after I pressed submit.

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Almost a week with this problem…

The connection will preferably be via Ethernet cable attached to the gateway. LiteBlue

Have you get it figured out yet?