By design, permission (see Tips) to edit a form card comes from its left card. This is because, for example, with Company+*tform, the edit permission is meant to govern who can edit each Company card. You may not wantto allow the same people to edit the format card itself.
We'd like a more intuitive interface; requires some design.
Set/Settings permissions.
more intuitive permissions of and by forms+discussed in support tickets
more intuitive permissions of and by forms+relevant user stories