I never have problem with this, I am using 32 GB external micro SD and no problem. Are U talking about storage which has phone only or included SD card?
Add 2. It s normal when U change external to internal storage (or conversely) as default storage, that phone doesnt see the app which was instaled before changing storage, but when when draped as it was originally, it will return back.
U can try use another viewer for image or music from playstore, if U see all images or music, ... If U are using SD card, it must be formated fat32 (not NTFS) or ext2/3/....
And place when U download files U can set in the internet browser properties.
Which ROM on your lenovo are U using?