del session.cookies['xxx'] and session.cookies.set('xxx', None) do not work properly

[dljjld]

Python 3.7.9 on Windows7
session = tls_client.Session(
client_identifier="chrome_109",
random_tls_extension_order=True,
)
session.get('https://httpbin.org/cookies/set/testcookie/12345')
session.get('https://httpbin.org/cookies/set/abc/67890')
print(session.cookies.get_dict())
print(session.get('https://httpbin.org/cookies').json())
del session.cookies['testcookie']
print(session.cookies.get_dict())
print(session.get('https://httpbin.org/cookies').json())
session.cookies.set('testcookie', None)
print(session.cookies.get_dict())
print(session.get('https://httpbin.org/cookies').json())

The result:
{'abc': '67890', 'testcookie': '12345'}
{'cookies': {'abc': '67890', 'testcookie': '12345'}}
{'abc': '67890'}
{'cookies': {'abc': '67890', 'testcookie': '12345'}}
{'abc': '67890'}
{'cookies': {'abc': '67890', 'testcookie': '12345'}}

Can fix it?