#1 : It's normal. It indicates that you've success enabling adoptable storage.
#2 : If you download & install from the Play Store, it uses the internal storage. Try download from outside source i.e Apkpure
The workaround is to enable adoptable storage, the method is much the same as enabling adoptable storage on Galaxy S7.
http://xda-developers.com/enable-adoptable-storage-for-galaxy-s7-and-s7-edge/