Select Audio Strip
Check Display Waveform (Properties Panel > Adjust > Sound > Display Waveform)
Adjust Start/End frames of the Hold Cut (Properties Panel > Time > Hold Offset Start/End
Usually only happens when adjusting the End frame for me
The first couple adjustments don't reproduce the error. Must adjust several times.
In order to refresh the audio to see the waveforms again, follow these steps:
Save your file
Go to File > Open Recent > The file you just saved