Using tab to change focus works in the arranger window but not the mixer window.
If I’m on the left panel I can only go to the center panel. Once. Then I can’t go left or right. Conversely, if I’m on the right panel I can only go to the center panel (via shift+tab). Once. Then I can’t go left or right.
Yes, I have exactly the same behaviour in Cubase Pro 14 on Mac Sequoia. For some reason I can tab back and forth between left panel and center panel in Mixer 4, but not in mixer 1-3.
Just upgraded to Windows 11 Pro 24H2. Same behavior. It’s working as expected in the arrange window, but SHIFT+TAB will only take you as far as the far-left pane. No wrapping to right side. Wrapping works when going forward with just TAB. Behavior in mixer window is the same as described in the OP.