What those screen captures show is the capability of the network connection (Speed) for the two devices. Not the actual network speed. Yes the My Cloud network port is Gigabit capable but one never see’s that max speed due to the hard drive within the My Cloud having a read/write speed significantly lower than 1000 Mbps and a number of other technical reasons. Same goes for the WiFi. There are various factors (encryption being one, network overhead being another) that reduce the WiFi’s actual speed versus it’s theoretical speed.
What you should do is run some speed tests using speed test software (not online websites that only test broadband speed) to test your local network’s actual read/write speed to the My Cloud. Various software out there like Crystal DiskMark (https://crystalmark.info/en/software/crystaldiskmark/) that can give one a general idea of the actual read/write speed to a My Cloud.
If the smartTV is Ethernet capable try using that rather than WiFi. If the smartTV is a far distance away from the WiFi router, try moving it closer and see if the issue persists.
How is the smartTV connecting to the My Cloud? Is it using a DLNA client app within the smartTV OS to access the DLNA (Twonky) Media Server on the My Cloud or a third party (like Plex) media server running on the local network? Or is the smartTV using a file manager type app to browse the local network and connect to the My Cloud using NSF or SMB?
And in your first post you indicated “… if i keep it below 20gb it is ok”. What are you keeping below 20gb? (Note that “gb” typically means Gigabytes.) The size of the media file being streamed? Where are you controlling (keeping below) what ever it is that is more than 20gb?
Edit to add: and just for comparison’s sake there are other discussions, like in the link below, showing read/write speeds others are getting with the single bay My Cloud devices.
