Thanks to all for your comments, much appreciated!

Here is some further info.

After clicking on the "eye" I see at the bottom of the Mixer track list the track 'Default Synth'. All yesterday I never saw such, now I do.

OK, so it turns out the Default Synth is playing. That's the sound I hear, and I see the meter with signal. If I drop the volume slider on the Default Synth then the sound goes away. OK, good.

However, the Mute button for the Default Synth does not work. If I click on it, it flashes, but does not light and does not mute.

If I Solo the Default Synth, all the other tracks get muted, but the Default Synth track a) is neither Muted nor Soloed visually (IOW, neither M nor S button is lit), but b) is in fact silenced.

This behavior doesn't make sense to me. Is it a bug?

All the above is observation of the "problem state".


BIAB for Windows 2023 (1006)