Yes, the hotkey assigned to command Switch Panes should move input focus from one pane to the other pane on comparing two text files. But I have just detected on testing it that it does not work anymore since UltraCompare v18.00. In previous UltraCompare versions the command works on being executed by key.

Please report this issue to IDM support by email. I do the same. The more users report an issue the higher becomes the priority for fixing it.

This issue of UltraCompare for Windows v18.00 is fixed with v18.10.0.38. The command Switch Panes with its default hotkey assignment Alt+Ctrl+S works again and switches input focus between the recent two text file comparison panes.

The command switches active pane between left and right pane on a text comparison of two text files. The input focus is always set to recent active line in the current pane and active line is displayed highlighted in both file panes.

The behavior is the same on a 3-way text comparison which means it is not possible to switch input focus with Alt+Ctrl+S to third recent pane. So if input focus is set with pointing device first on middle pane, next on right pane and last on left pane, the command Switch Panes switches input focus respectively active pane between right and left pane. The middle pane cannot be activated with Alt+Ctrl+S. So with left pane being currently the active pane it is necessary to use the pointing device to make the middle pane the active pane. Then command Switch Panes switches active pane between left and middle pane and right pane must be activated with the pointing device.

I wrote an enhancement request for command Switch Panes to rotate between all three panes in recent active order on a 3-way comparison session.