(am) Except as provided in par. (b) or s. 938.368, an order under this section or s. 938.357 or 938.365 made before the juvenile attains 18 years of age that places or continues the placement of the juvenile in a foster home, group home, or residential care center for children and youth, in the home of a relative other than a parent, or in a supervised independent living arrangement shall terminat