Variaudio not available

I have this track with all the audio in Musical Mode and something is puzzling me. Some of the audio shows regular warp markers in the lower pane and if I unset Musical Mode they disappear (and the audio goes a bit haywire); others don’t have warp markers, even though they too are in Musical Mode. So that’s the first thing: I don’t understand why. I thought it might be Quantise but resetting it didn’t help.

The other is that Variaudio isn’t available for the audio with the warp markers. The Edit button is lit up but the controls are greyed out. Switching off Musical Mode on these parts makes no difference. After bouncing, the new part behaves in exactly the same way.

Can anyone explain this please?