Some Samsung Android 13 firmwares seem to be affected by the issue which denies system file access component access to the files.
Please ensure that system External storage component has access to files:
- phone Settings, search: Special access
- All files access, open it and then click the menu button and hit Show system
- make sure External storage is enabled
Then in Poweramp use Rescan option (from list header menus or from Settings / Library).