Balance request returns either 0 or error

[qper228]

blockchain-wallet-service -V: 0.26.3

nodejs -v: v8.10.0

after I send request to fetch wallet balance :

params = { 'password': self.decode_password(), 'api_code': APP_KEYS['blockchain'], } r = requests.get(f'http://localhost:3000/merchant/{self.guid}/balance', params=params)

I'm getting either this response: {"error":"Unexpected error, please try again"} either this {"balance":0} But I know for sure my wallet doesn't have zero balance... Sometimes, rarely sometimes, it begin to work once I restart Blockchain wallet service, but mostly it doesn't. I'm experiencing this issue already quite long time since last week already , can you help me please this is really bad