Media Encoder 15.1 does not render all tracks to stereo AAC
Found a bug in Media Encoder 15.1.
Try to transcode clip with 12 tracks of audio into stereo AAC in Media Encoder
Expected behavior: All 12 audio tracks get mixed down to two stereo tracks in exported clip
Actual behavior: Only first 6 tracks get mixed down to two stereo tracks, and tracks 7-12 are silenced
For what it's worth, trying the same thing out of Premiere 15.0.0 directly does actually work: all 12 tracks do correctly get mixed down into two stereo AAC tracks.
This is on Windows 10 19042.928.
Attached is an image of the track layout of the clip getting transcoded. Tracks 1-6 run through the first 11 minutes, and tracks 7-12 after that to the end of the 14-minute clip.