Steps To Reproduce:

1. Hierarchy > right click
2. 3D Object > cube
3. Go to Windows > Sequencing > Timeline.
4. Select cube and click "Create" in the timeline window
5. Click on the record button next to animation track
6. Move the cube at different intervals to make a short clip
7. Stop the recording and hit play

Actual Result: Animation doesn't play and the marker doesn't move at all.

Expected Result: The recorded animation should play.

Reproducible On: 2018.3.0a5, 2018.3.0a3

Working Fine On: 2018.3.0a2

Environment: Occurs on Windows and Mac.