I recently copied all my files from my SD-Card ("formatted as Internal Storage") to a safe location, then copied those files to the "Internal storage" part of the rom that opens up after the SD-Card was gone. It worked. on Android 10. Maybe that change was later. Android storage looks weird from the outside anyway. It was as if only the publically visible files Apps want you to see got on the SD-Card, and then each app has some hidden folder (that apps like termux or apps with custom-built file pickers sometimes kind of let you half-guess the structure of (my head: no details) and) that appeared to have been on the built-in rom all along. That copy operation now lets me remove my SD Card w/o moving all my Images and less than half of my apps files.