Repro steps:
1. Open "case_820593-Repro1" project
2. Go to Assets/RPG/Audio/SFX
3. Reimport .wav files
4. Get FSBTool ERROR: Failed decoding audio clip.

Note: I stripped the project and attached the .zip version. Only bigger .wav files reimport without errors (for example 239kb). Files that fail to reimport are approximately between 4kb and 75kb.

Actual behavior: smaller .wav files do not reimport correctly and causes console error: FSBTool Error: Failed decoding audio clip.
Expected behavior: all .wav files reimport without errors

Reproduced on: 5.3.6p3, 5.4.0f3, 5.5.0a6
Did not reproduce on: 5.3.5f1, 5.2.4f1