When writing in succession with the strage access framework, only the first file is written

We are creating an android application. I want to perform file operations in succession, but when I start the picker and write to saf (strage access framework) in succession, only the first file is written and the subsequent files are not written.

What I would like to achieve

I want to start and write the picker continuously in saf and make all files work properly.

Source code for this.

class MainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        (0..2).forEach {
            val intent = Intent().apply {
                type = "*/*"
                action = Intent.ACTION_CREATE_DOCUMENT
                putExtra(Intent.EXTRA_TITLE, "test$it.txt")
                putExtra(
                    DocumentsContract.EXTRA_INITIAL_URI,
                    Uri.parse("content://com.android.externalstorage.documents/document/primary%3ADownload")
                )
            }
            testFileCreate.launch(intent)
        }
    }

    private val testFileCreate = registerForActivityResult(ActivityResultContracts.StartActivityForResult()) { result ->
        try {
            contentResolver.openOutputStream(result.data?.data!!) .use { outputStream ->
                outputStream?.write("testdata".toByteArray())
            }
        } catch (e: Exception) {
            e.printStackTrace())
        }
    }
}

What we tried.

When I started and closed each one individually, it worked fine, but when I started the next one before closing the previous saf, it did not work except for the first one.

I was able to create it using ActivityResultContracts.OpenDocumentTree(), but since android12, I cannot use OpenDocumentTree because the download folder is not available. Also, we are not using MANAGE_EXTERNAL_STORAGE because it may not pass the screening process and because it works more stably using a picker (filer).

Supplemental information (FW/tool versions, etc.)

android 12