Audition 25: Substracting a file from itself (mix paste with inverted signal) is not zero

When substracting a file from itself (e.g. stereo, 48 kHz, 16 bit integer) via Mix Paste of the inverted signal is not zero in Adobe 25. In previous Adobe versions, it has worked out fine.

Steps to reproduce:

1) Copy a file "test.wav" to "test_copy.wav" on your computer

2) Open both files, "test.wav" and "test_copy.wav" in Audition

3) Select and copy the complete file "test.wav" (Ctrl+A, Ctrl+C)

4) Select the file "test_copy.wav"

5) Open Mix Paste -> Check "Invert Copied Audio"; make sure that the level is both at 100%, and cross-fading is disabled. Insert the copied audio via "Overlap (Mix)".

Expected behavior: When substracting the file from itself, the result should be (digital) zero. What we however see is that it results in a low-level signal (approx. up to 50 on PCM scale). Same also happens when the insertion is done directly from file instead of the clip-board).

Affected version: Adobe Audio 25.0.0.47, macOS (Intel)