google oauth2 refresh token expiration

Hello,

I setup fetchmail to get email from gmail according to README.OAUTH2. It works for exactly a week and then stops:

$ ./fetchmail-oauth2.py -c ... --refresh
Traceback (most recent call last):
  File "/home/user/./fetchmail-oauth2.py", line 567, in <module>
    main(sys.argv)
  File "/home/user/./fetchmail-oauth2.py", line 479, in main
    response = RefreshToken(cfg['client_id'],cfg['client_secret'],reftok,
  File "/home/user/./fetchmail-oauth2.py", line 368, in RefreshToken
    response = urlopen.urlopen(token_url,
  File "/usr/lib64/python3.10/urllib/request.py", line 216, in urlopen
    return opener.open(url, data, timeout)
  File "/usr/lib64/python3.10/urllib/request.py", line 525, in open
    response = meth(req, response)
  File "/usr/lib64/python3.10/urllib/request.py", line 634, in http_response
    response = self.parent.error(
  File "/usr/lib64/python3.10/urllib/request.py", line 563, in error
    return self._call_chain(*args)
  File "/usr/lib64/python3.10/urllib/request.py", line 496, in _call_chain
    result = func(*args)
  File "/usr/lib64/python3.10/urllib/request.py", line 643, in http_error_default
    raise HTTPError(req.full_url, code, msg, hdrs, fp)
urllib.error.HTTPError: HTTP Error 400: Bad Request

It starts to work again for a week after I use fetchmail-oauth2.py --obtain_refresh_token_file.
Could it be because my Google app in OAuth consent screen has Publishing status: Testing?

Regards,
Nerijus