[2.7.8] Audio Copy mode bug?

[Misha]

After copy, the bit rate mode was changed from Variable to Constant.
Is there possible to copy with no changes? (Include tags)

[eumagga0x2a]

In copy mode, audio bitstream is never changed. Some packets may be dropped when necessary to maintain A/V sync (especially at the stream start and at the end). For any in-depth answer, please provide more than zero details*.

You should also consider updating to the latest nightly, the 2.7.8 release has got long in the tooth.

*) Properties of the source file as listed by MediaInfo, properties of the output file as listed by MediaInfo, admlog.txt from loading and processing the source video.