Why does switching display groups not restore their saved layout?

Enable Apply Automatically in App Menu > Tools > Groups to reapply eligible layout protections when you change groups through that menu. It starts off. You can also choose Apply All Protections there whenever you want to restore the available rules immediately.

Enabling a group and applying its layout are separate operations. The group must be active, its layout features must be enabled, and the participating displays must be connected and suitable for the saved rules. An enabled group can remain inactive because of its membership or priority conditions.

For a complete two-monitor setup, follow Keep your monitor arrangement and main display consistent after wake.

Hold Option while choosing a group to disable the other groups and enable only that one. With Apply Automatically enabled, this also reapplies the eligible layout protections. The group still needs to meet its activation conditions after you enable it.

Applying layout protections requires Pro. The automatic menu option covers changes made through this menu, not every Settings edit or other group-state change. See Groups menu and Layout Protection for the separate startup and display-reconfiguration behavior.