Alright, i test again. Now i got it 5K video quality in YouTubeOnce you have the output file done. Just right-click the file, go in properties and tell me what the detailed information says in resolution. Also as a note, remember youtube can take up to 4 hours before will be rendered to 4-5K. Depend on how busy our are youtube servers.
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This time i change from H.265 to H.264 and resolution size remain the same which is 5,120 (W) x 2,880 (H)