Got the logs. Ok, I need the XML to verify, but it appears that your file has the TrueHD as the first audio track and the AC3 as the second audio track. Your TiVo cannot direct play the second audio track, it can only play the first audio track. So PMS has to remux the file to make the AC2 the first audio track. The TiVo doesn’t support hevc when direct streaming, so it has to transcode the video to h264. The TiVo also does not support 4k h264, so it has to lower to 1080p. If you want, try remuxing your original file making the AC3 the first audio track. See if that file then direct plays.
