Clip attributes - change number of audio tracks

Changing the amount of audio tracks for a clip in clip attributes (in this case FS7 4K .mxf) has no effect.
I try changing from 8 to 2 and nothing happens - it's locked at 8 tracks of audio.
Beta 6
nMP D700 32GB RAM
MacOS 10.12.5
Cheers,
Mike Kelland
I try changing from 8 to 2 and nothing happens - it's locked at 8 tracks of audio.
Beta 6
nMP D700 32GB RAM
MacOS 10.12.5
Cheers,
Mike Kelland