503 Server Error: No healthy IP available for the backend for url: ...

[MPeti1]

I was just batch-downloading chat from a channel and got this error:

Traceback (most recent call last):
  File "c:\users\masap\appdata\local\programs\python\python37\lib\runpy.py", line 193, in _run_module_as_main
    "__main__", mod_spec)
  File "c:\users\masap\appdata\local\programs\python\python37\lib\runpy.py", line 85, in _run_code
    exec(code, run_globals)
  File "C:\Users\masap\AppData\Local\Programs\Python\Python37\Scripts\tcd.exe\__main__.py", line 7, in <module>
  File "c:\users\masap\appdata\local\programs\python\python37\lib\site-packages\tcd\__init__.py", line 92, in main
    Downloader().channels(Arguments().channels)
  File "c:\users\masap\appdata\local\programs\python\python37\lib\site-packages\tcd\downloader.py", line 195, in channels
    self.video(video)
  File "c:\users\masap\appdata\local\programs\python\python37\lib\site-packages\tcd\downloader.py", line 100, in video
    for comment in video.comments:
  File "c:\users\masap\appdata\local\programs\python\python37\lib\site-packages\twitch\v5\resources\comments.py", line 22, in __iter__
    fragment = self.fragment(fragment['_next'])
  File "c:\users\masap\appdata\local\programs\python\python37\lib\site-packages\twitch\v5\resources\comments.py", line 16, in fragment
    return self._api.get(self._path.format(video_id=self._video_id), params={'cursor': cursor})
  File "c:\users\masap\appdata\local\programs\python\python37\lib\site-packages\twitch\api.py", line 111, in get
    return self.request('GET', path, ignore_cache, params=params, headers=self._headers(headers), **kwargs)
  File "c:\users\masap\appdata\local\programs\python\python37\lib\site-packages\twitch\api.py", line 100, in request
    response.raise_for_status()
  File "c:\users\masap\appdata\local\programs\python\python37\lib\site-packages\requests\models.py", line 940, in raise_for_status
    raise HTTPError(http_error_msg, response=self)
requests.exceptions.HTTPError: 503 Server Error: No healthy IP available for the backend for url: https://api.twitch.tv/v5/videos/1025863747/comments?cursor=eyJpZCI6IjgzYjc1NWRiLTZlMTAtNDllZC04NmZkLWFjYzI4NGM0NzM2OSIsImhrIjoiYnJvYWRjYXN0OjQyMDk2NTcwNDQ0Iiwic2siOiJBQUFGczV0dWswQVdmLXZUVG9xV1FBIn0f

Actually, I was downloading from 2 channels at the same time, and both of them stopped with this same error.
I think the tool could have an infinite (but delayed) retry for such HTTP codes (which may be anything that is not 2XX or 404)