I have a Galaxy J7 Sky Pro with a 128 GB SD card “adopted” as storage, although apps don’t install there by default and must be transferred to it. I have several apps now running from that card. This phone is not rootable, so this cannot be changed. There is 16 GB internal storage.
My android internal storage shows 12.73 GB storage used due to apps, but when I use a calculator to add the total storage used by individual apps, it comes to only ~5.87 GB used. Where is the other 6.86 GB coming from? Is there some sort of hidden storage belonging to apps? Are there hidden internal apps? This does not appear to reflect the OS, since the phone shows full when app storage reaches about 14 GB.
How do I browse the internal storage of this phone to be able to determine where the hidden files are and which apps they are related to?