How to reproduce:
1. Open the attached '1279412.zip' project and the 'SampleScene' Scene
2. Enter the Play mode
3. Exit the Play mode
4. In the Hierarchy window select 'Playable Graph'
5. In the Inspector set the Update Mode of the Animator component to 'Animate Physics'
6. Enter the Play mode

Expected result: The audio track plays both times
Actual result: The audio track doesn't play when the Update Mode is set to 'Animate Physics'

Reproducible with: Timeline 1.2.6, 1.4.1, 1.5.0-preview.5 (2019.4.11f1, 2020.1.8f1, 2020.2.0b5)
Cannot test with: 2018.4.27f1 (due to errors)