I have found a variety of m4A files which when converted by dBpoweramp export at a significantly lower volume than the source files (approximately 70%).

The source have no ReplayGain tags. I am not applying any DSP Effects.

If I use a third party tool to convert the m4a to wav and then use dBpoweramp, the output is correct. If I use some other m4a files, the output is correct.

What could be causing dBpoweramp to decode certain AAC files incorrectly?

If a developer would like to test the file, please contact me directly.

SourceFile info:
General
Format : MPEG-4
Format profile : Apple audio with iTunes info
Codec ID : M4A (M4A /mp42/isom)

Audio
Format : AAC LC
Format/Info : Advanced Audio Codec Low Complexity
Codec ID : mp4a-40-2
Duration : 3 min 48 s
Bit rate mode : Variable
Bit rate : 256 kb/s
Maximum bit rate : 320 kb/s
Channel(s) : 2 channels
Channel layout : L R
Sampling rate : 44.1 kHz
Frame rate : 43.066 FPS (1024 SPF)
Compression mode : Lossy