Решение
Try File - Preferences - Dashboard within PGAdmin. See if toggling those options will bring it back.
If not, then providing you do not have any customised layout, try File - Reset Layout.
Другие советы
Right click on the menu and go to 'Add Panel'. You will find 'Dashboard' in the drop down menu. Click on it and the dashboard tab will open.
Не связан с dba.stackexchange