AssertionError: daemonic processes are not allowed to have children

[ppt000]

I get the following error multiple times after a single (but long) get request:

Error in atexit._run_exitfuncs:
Traceback (most recent call last):
  File "C:\Users\Paolo\AppData\Roaming\Python\Python37\site-packages\firebase\__init__.py", line 13, in close_process_pool
    process_pool.close()
  File "C:\Users\Paolo\AppData\Roaming\Python\Python37\site-packages\firebase\lazy.py", line 10, in __getattribute__
    return getattr(object.__getattribute__(self, "_obj_fn")(), name)
  File "C:\Users\Paolo\AppData\Roaming\Python\Python37\site-packages\firebase\multiprocess_pool.py", line 11, in get_process_pool
    _process_pool = multiprocessing.Pool(processes=size)
  File "C:\Program Files\Python37\lib\multiprocessing\context.py", line 119, in Pool
    context=self.get_context())
  File "C:\Program Files\Python37\lib\multiprocessing\pool.py", line 177, in __init__
    self._repopulate_pool()
  File "C:\Program Files\Python37\lib\multiprocessing\pool.py", line 238, in _repopulate_pool
    self._wrap_exception)
  File "C:\Program Files\Python37\lib\multiprocessing\pool.py", line 257, in _repopulate_pool_static
    w.start()
  File "C:\Program Files\Python37\lib\multiprocessing\process.py", line 110, in start
    'daemonic processes are not allowed to have children'
AssertionError: daemonic processes are not allowed to have children

Any idea why the library seems to launch multiple processes?
It looks like it relaunches the main script as well multiple times.