ID 267226 - Audio doesn't cache and playback correctly in audio only sequences

Problem summary
Audio doesn't cache and playback correctly with audio only sequences

Customer reported version
Hiero10.5v2

Customer reported platform
10.11

Steps to reproduce

1) Open NukeStudio/Hiero 10

2) Import a .wav file and add it to a new sequence

3) Delete the video track

4) Edit the track by cutting and moving sections, eventually, the Viewer cache will only load upload the end of the last edited clip, shown below:

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5) Playing past the end of the cached region doesn't show the time indicator move, but the audio still plays.

Workaround
Add an empty video track, as the problem seems to not occur with one.

Reproduced by support
This problem has been reproduced on:
Nuke 10.5v2 - Windows 10 -  MacOSX 10.12
Nuke 10.5v1 - Windows 10 
Nuke 10.0v6 - Windows 10
Nuke 10.0v1 - Windows 10 - CentOS 6.7 - MacOSX 10.12

This was not an issue on:
Nuke 9.0v8 - Windows 10 - CentOS 6.7 - MacOSX 10.12
Nuke 9.0v1 - Windows 10

Expected behaviour
For Nuke to playback the audio correctly

Actual behaviour
It didn't cache the whole timeline, and would playback audio without the time indicator moving.