This is a known problem https://github.com/TeamWin/Team-Win-Recovery-Project/issues/943 , no solution yet, but it's on the todo list
Sorry, this is a TWRP, not a migrator. You can use Titanium backup and Migrate apps for that.
Flash stock rom via fastboot (there's a flash_all.bat inside the fastboot rom). I have made a special version for Global Mi9SE users(in the telegram group), but it's best if you use fastboot.Maybe I didn't explain myself correctly. I don't need to migrate apps, but ROM, I want to go back from rom cDroid to Stock Miui, but when I flash stock rom (zip) I get an error of treble, and when I try to flash via miflash the screen on the phone go dark and says "press any key to shutdown"
fastboot flash recovery twrp-PUTVERSIONHERE-Mi9SE.img
fastboot --disable-verity --disable-verification flash vbmeta vbmeta.img
Just some Info:
Android has chandeg from FDE (full disc encryption) to FBE (file based encrytion) with the upgrade to Android 10.
That gave me headache in the earlier HTC M7/M9 and Mi MIX times years ago - maybe there is a quickwin possible by changing the recovery.fstab or twrp.fstab to a compatible FBE mode.