Have a look under options on the exposure dialog. There should be a group by slot option for the filters. If that's on then it will shoot all red then all blue then all green ....
It looks like it's only active with a camera connected. There is also a minor bug here, click on options and the menu will only pop right of the arrow so if the dialog is too close to the edge of the screen it closes real fast. Move the dialog to the left a bit
