When switching from one custom workspace to another, the Audio Mixer window remains empty

1. The sequence is opened in the custom "Editing" workspace. Screen 01
2. For further editing, the same sequence is opened in the custom "Audio" workspace. The sequence remains open in the Timeline window. It simply switches to the custom "Audio" workspace. No faders are displayed in the Audio Track Mixer window, even though the sequence contains audio tracks. Screen 02
3. The same sequence is reloaded into the Timeline window by double-clicking it from the Project window. The faders for the existing audio tracks now also appear in the Audio Track Mixer. Screen 03

The problem can also be reproduced by switching between the default workspaces "Editing" and "Audio".