There is a known issue that happens when trying dock a control panel over another control panel after updating Dimension from version 5.05 to version 5.06. Once the procedure below is followed, it will fix the issue.
To explain the procedure, we will use Control Panel 1 as the "Base" control panel & Control panel 2 as the "Stacked" control panel. The "Base" control panel is the control panel that is docked in the original location. The "Stacked" control panel is the control panel that is stacked on top of the "Base" panel.
Now Control Panel 2 is stacked under Control Panel 2.