Multiple page plugin settings

WordPress always saves all options in one group at the same time. So if you have a page with only a part of the options in the group, the rest will be saved as ‘unset’.

There are two possible paths to a solution. The easy one is to include all options in every page and use css to hide some of them. They will then be saved unchanged. The other one is splitting the option group into three groups.

Considering the menus: if you set the first page as both the main menu entry and the first submenu entry, you’re done.