@Mitrom Try submitting an error report through the Samsung Members app about this issue!
What software version is your Note20/WhatsApp messenger on?
What software version is your Note20 on? Settings > About Phone > Software Information > Build Number (last 4 characters)
See release notes Samsung blocked it 😞
App copies made using Dual messenger can no longer access SD card files directly. To share SD card files in an app copy, select the files in Gallery or My Files, tap Share, then select the app copy.