When "Dropdown first entry" set to "none" and not "all" in general settings, the active group and host go to "non selected" after editing templates.
As a result, you have to re-click on the template tab and locate the template you were editing if you want to modify something else.

Same behavior is also show when viewing the Dashboard and latest data.
If you are in the dashboard and go to latest data for an item in "Last 20 issues" you will be thrown into "non selected" groups and "non selected" host.
If "all" is selected for "Dropdown first entry" these problems do not occur.