Python 当第二个人开始输入凭证时，电报机器人（telebot）停止响应

当第二个人开始输入凭证时，电报机器人（telebot）停止响应。我相信问题出在chat.input（）中，但我不确定，也不知道如何解决它。我试过的都不管用。当为第二个人运行ask_credentials（）时，它会冻结。顺便问一下，我是OOP新手，代码OOP够了吗

代码的主要部分：

class Chat:
    global existing_chats
    global local_order_count
    def __init__(self, chat, request):
        self.request = request
        self.previous_answer = None
        self.chat_params = chat
        self.chat_id = chat.chat.id
        self.answer = None
        self.answernotrecieved = None
        self.status = True
        self.keep_waiting = True

        for existing_chat in existing_chats:
            if existing_chat.chat_id == self.chat_id:
                existing_chat.keep_waiting = False
                del existing_chat
                

    def input(self, question):
        if self.chat_params:
            self.answer = bot_.send_message(self.chat_params.chat.id, question)
            self.answernotrecieved = True
            bot_.register_next_step_handler(self.answer, self.return_answer)
            while self.answernotrecieved and self.keep_waiting:
                time.sleep(1)
                pass
            if not self.answernotrecieved:
                return self.answer.text
            else:
                return None

    def return_answer(self, answer):
        self.answer = answer
        self.answernotrecieved = False

    def say(self, message):
        if self.chat_params:
            bot_.send_message(self.chat_params.chat.id, message)

    def __del__(self):
        print('deleting chat')




class Order:
    global existing_chats
    global local_order_count
    def __init__(self, chat):
        self.chat = chat
        self.context = {'city': ['Kiev', False,'^\b[a-zA-Z0-9_]+\b$'],
                        'name': [None, 'What is your full name?', '\w\s+\w+'],
                        'bdate': [None, 'What is your date of birth (dd-mm-yyyy) split with "-"?','[0-9]{2}-[0-9]{2}-[0-9]{4}'],
                        'nation': [None, 'What is your nationality (e.g. Ukraine)?', '\w'],
                        'gender': [None, 'What is your gender Male/Female?', '\w'],
                        'passport': [None, 'What is your passport number?','\w'],
                        'flight_date': [None, 'What is your flight date (dd-mm-yyyy) split with "-"?','[0-9]{2}-[0-9]{2}-[0-9]{4}'],
                        'email': [None, 'What is your email, we will send you the results?','^[a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+\.[a-zA-Z0-9-.]+$'],
                        'tdate': [None, False, False],
                        "rdate": [None, False, False]}
        self.notsent = True
        self.ask_credentials()
        

    def ask_credentials(self):
        try:
            for key, [credential, question, form] in self.context.items():
                if not credential and question and self.chat.keep_waiting:
                    self.reply = self.chat.input(question)
                    if self.reply is not None:
                        if re.search(form,self.reply) or not form:
                            
                            self.context[key] = [self.reply, question, form]
                        elif not re.search(form,self.reply):
                            
                            self.ask_credentials()
                        elif not form:
                            pass
                    else:
                        break
            else:
            
                try:
                    for key, [credential, question, form] in self.context.items():
                        if (type(credential)==str) and question and form:
                            pass
                except ValueError:
                    self.ask_credentials()
                else:
                    self.check_credentials()
        except:
            pass

class Login(threading.Thread):
    def __init__(self, chat_params):
        threading.Thread.__init__(self)
        self.chat = Chat(chat_params, self)
        self.chat_params = chat_params
        existing_chats.append(self.chat)
        if self.chat.status:
            self.chat.say(
                f'Dear {chat_params.from_user.first_name}, \n****')
            self.chat.say('To get the AI Lab Password, contact us on instagram')
            self.password = self.chat.input('Enter your AI Lab password:')
            self.login(self.password)

    def login(self, password):
        global existing_chats
        global local_order_count
        if password in pass_list:
            self.chat.say('Access Granted. Lets enter your credentials.')
            print(f'New Order #{local_order_count} '
                  f'at {datetime.now().strftime("%Y-%m-%d %H:%M")} '
                  f'by {self.chat_params.from_user.first_name} '
                  f'@{self.chat_params.from_user.username}')
            local_order_count += 1
            order = Order(self.chat)
        else:
            if password:
                if '/' not in password:
                    self.chat.say('Access Declined. Press /start')


@bot_.message_handler(commands=["start"])
def start(chat_params):
    Login(chat_params)