Sorry, I don't see that tag. I looked at every tag in JRiver and with exiftool. Am I looking in the wrong place?
The same song converts perfectly on the command line with the same syntax, if that matters.
ExifTool Version Number : 12.57
File Name : 07 - Peace Train.m4a
Directory : Y:/music/ALAC/10,000 Maniacs/10,000 Maniacs - In My Tribe (1987) [FLAC] {9 60738-2}
File Size : 22 MB
File Modification Date/Time : 2023:03:02 23:12:47-07:00
File Access Date/Time : 2446:05:10 16:38:55-06:00
File Creation Date/Time : 2023:03:02 23:12:47-07:00
File Permissions : -rw-rw-rw-
File Type : M4A
File Type Extension : m4a
MIME Type : audio/mp4
Major Brand : Apple iTunes AAC-LC (.M4A) Audio
Minor Version : 0.2.0
Compatible Brands : isom, iso2
Media Data Size : 22096785
Media Data Offset : 40
Movie Header Version : 0
Create Date : 0000:00:00 00:00:00
Modify Date : 2021:08:27 18:26:31
Time Scale : 1000
Duration : 0:03:27
Preferred Rate : 1
Preferred Volume : 100.00%
Preview Time : 0 s
Preview Duration : 0 s
Poster Time : 0 s
Selection Time : 0 s
Selection Duration : 0 s
Current Time : 0 s
Next Track ID : 2
Track Header Version : 0
Track Create Date : 0000:00:00 00:00:00
Track Modify Date : 2021:08:27 18:26:31
Track ID : 1
Track Duration : 0:03:27
Track Layer : 0
Track Volume : 100.00%
Matrix Structure : 1 0 0 0 1 0 0 0 1
Media Header Version : 0
Media Create Date : 0000:00:00 00:00:00
Media Modify Date : 2021:08:27 18:26:31
Media Time Scale : 44100
Media Duration : 0:03:27
Media Language Code : und
Handler Description : SoundHandler
Balance : 0
Audio Format : alac
Audio Channels : 2
Audio Bits Per Sample : 16
Audio Sample Rate : 44100
Handler Type : Metadata
Handler Vendor ID : Apple
Title : Peace Train
Artist : 10,000 Maniacs
Album : In My Tribe
Track Number : 7 of 12
Disk Number : 1 of 1
Content Create Date : 1987:07:27
Beats Per Minute : 104
Encoder : Lavf58.20.100
Initial Key : D
MusicBrainz Album Release Country: CA
Media : CD
Original Year : 1987
Length : 3:27
Script : Latn
MusicBrainz Album Type : album
Label : Elektra
Catalog Number : CD 60738
MusicBrainz Album Status : official
Original Date : 1987-07-07
Barcode : 075596073820
ISRC : USEE10301543
Artists : 10,000 Maniacs
MusicBrainz Album Id : 17be410b-4ec0-46f3-8eec-a7390e262c66
Acoustid Id : 81cf5a11-eb1b-491f-9557-72614af5a4dd
MusicBrainz Release Group Id : 94d44c63-7dee-3921-aa6e-b28b27753cfa
MusicBrainz Track Id : b75b23ad-fa89-4006-88e4-3253ad9fd6e2
MusicBrainz Album Artist Id : b9a06530-1241-4162-836f-7b8e79deaa58
MusicBrainz Artist Id : b9a06530-1241-4162-836f-7b8e79deaa58
MusicBrainz Release Track Id : c2ee7874-d392-4dcf-8a9d-b0a3417e81a4
Mood : Not acoustic, Not aggressive, Not electronic, Happy, Not party, Relaxed, Not sad
Cover Art : (Binary data 172794 bytes, use -b option to extract)
Album Artist : 10,000 Maniacs
Sort Album Artist : 10,000 Maniacs
Sort Artist : 10,000 Maniacs
Genre : Pop/Rock
Tool Name : Media Center
Tool Version : 28.0.106
Rating : 10
HDCD : -1
Track Transition Duration : -1
Avg Bitrate : 855 kbps