Just migrated from a DS916 to DS918 at the recommendation of others (upgraded to 2x4GB, using the synology ram). The issue I had with 1080i is completely resolved (Hooray!) However when playing to my iPhone X, 720p now buffers. This seems to be because it's trying to transcode to HEVC. Playback of the same content to an iPad which uses h264 works flawlessly.
So, can I force encoding to h264 for all content? If not possible at the server level, is there a way to setup client profiles so that HEVC is not used? (also open to any other better options)