[Stiglr]

Make sure you're in Group Select mode (the triple-box button under Select at the top left). Select all the objects that are in the group by clicking on any one of them; all objects in the group will be selected.

UNgroup them with Edit>Ungroup.

Select all the objects again. Use "Merge" to make them one object (even if they're not one contiguous geometry. Object>Merge or Ctrl + Shift + M.

Also, as you work, make sure of which Select button you've got depressed, Object or Group, before making selections or doing anything. Simply put, if you're not in Group Select mode, you will select individual (non-contiguous) objects separately.