I have problems when trying to stream the videos from my My cloud home when I am away.
The videos load incredible slow, and even when i turn the quality down to 480p it still struggles to keep up. UPnP is enabled, so I have a Direct/PortForward mode. As you can see of the following picture, my internet speed shoud not be the problem. 20mbps should be plenty of upload? The place where I try to stream the videos also have more than enough download.
Try not to use video transcoding, especially not HEVC / x265 transcoding.
Only use it for direct streaming, you can select it in the quality settings in the Plex client.