Audio Waveform not showing in Multicam Proxy View

I have an issue I can not find the solution to!

I have 4 camera angles and one audio track combined into a multicam clip. I only use the audio of the main audio track for the entire multicam clip. When I use Proxy Media the waveform of the main audio does not show in the timeline (it shows red). This is only an issue in multicam, because when I import the audio separately into the timeline it shows the waveform. I believe the problem lies in the fact that I imported the audio as an 'angle'. Has anyone found a solution to this issue?