Apple Homepod mini was initially playing apple music stream at the same time as watching apple tv movie,all the information related to setting up changes in apple tv 4K.
non of the solutions in Apple tv + drop downs had Homepod mini options showing.
The solution i found was when playing a something i apple tv + to press and hold down the tv scren symbol button on the apple tv + remote, a sub screen will appear on the right of the picture with an airplay symbol at the bottom activate that symbol and a choice of speaker options will appear with tick box actions availible.
