micropy-cli: Not work on Pyboard (and clones)

micropy-cli version 2.1.0 not work on Pyboard (STM32F405RGT6 MCU) and it’s clones. stubs generation end with errors. On ESP32 work without problems.

micropy stubs create COM8
...
MicroPy  Pyboard  Stub module: writer
MicroPy  Pyboard  Stub module: ymodem
MicroPy  Pyboard  Stub module: zlib
MicroPy  ✔ Done!
MicroPy  Copying stubs...
Source directory /pyboard/stubs does not exist.
Traceback (most recent call last):
  File "d:\applications\python37\lib\runpy.py", line 193, in _run_module_as_main
    "__main__", mod_spec)
  File "d:\applications\python37\lib\runpy.py", line 85, in _run_code
    exec(code, run_globals)
  File "D:\Applications\Python37\Scripts\micropy.EXE\__main__.py", line 9, in <module>
  File "d:\applications\python37\lib\site-packages\click\core.py", line 764, in __call__
    return self.main(*args, **kwargs)
  File "d:\applications\python37\lib\site-packages\click\core.py", line 717, in main
    rv = self.invoke(ctx)
  File "d:\applications\python37\lib\site-packages\click\core.py", line 1137, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "d:\applications\python37\lib\site-packages\click\core.py", line 1137, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "d:\applications\python37\lib\site-packages\click\core.py", line 956, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "d:\applications\python37\lib\site-packages\click\core.py", line 555, in invoke
    return callback(*args, **kwargs)
  File "d:\applications\python37\lib\site-packages\micropy\cli.py", line 224, in create
    return mp.create_stubs(port, verbose=verbose)
  File "d:\applications\python37\lib\site-packages\micropy\main.py", line 83, in create_stubs
    stub_path = next(out_dir.iterdir())
StopIteration

After physically device disconnect-connect there is stub files visible on filesystem.
Main difference of this boards is internal fs exposed as USB mass storage device. Disabling USB MSD not solve this problem.