The release notes says under Settings Resolved Issues:
- Storage graph and size information in Settings now updates correctly. (32295963)
However, this doesn't seem to be the case. When I went from PB 3 to 4, it had deleted all of my downloaded Apple Music, signed me out of App Store and iTunes store, and signed me out of Apple Music and turned off iCloud Music Library.
However, the previously downloaded music still showed under iPhone Storage as Media. So, I re-enabled Apple Music, went into Phone Storage settings and removed all of the downloaded music in one go, just to start fresh.
However, now when I open iPhone Storage, the graph will show me as using almost all the device space as I previously was (I was using about 55 out of 64 GB with all of the music on there on PB3), but it says at the top using 33.8 out of 64. However, I can tap on one of the sections at the bottom (say, Photos), and then immediately go back, and the graph will update itself to show what I assume is the correct reading.
The two attachments were taken one after the other after doing the above. Something with the storage graph is still wonky.