Polarbear produces signature result which is different from "cetcli tx sign"

[ngugcx]

OS: Ubuntu 16.04.
Two issues:

• Polarbear produces signature result which is different from "cetcli tx sign"
• Polarbear produces different signature results with the same input.

The following python3 code can reproduce the issues on Ubuntu 16.04.

secret = 'xxxxxxxxx'
chain_id = 'coinexdex2'

# init wallet
import ctypes
from pathlib import Path
home = str(Path.home())
path = '{}/.cetcli/keys'.format(home)
lib = ctypes.CDLL('/home/ubuntu/exchanges-res/coinexdex/polarbear/sdkforpython/wallet_linux.so')
# lib = ctypes.CDLL('/home/ubuntu/exchanges-res/coinexdex/polarbear/wallet.so')
lib.BearInit(path.encode('utf-8'))
key_name = '0a542970-9fc7-11ea-a52f-00163e024c1c'

# get account_number and sequence
account_number = '339981'
sequence = '3' 

# sign and broadcast
sign = lib.SignAndBuildBroadcast
sign.restype = ctypes.c_char_p

unsigned_tx_bytes = '{"type":"cosmos-sdk/StdTx","value":{"msg":[{"type":"bankx/MsgSend","value":{"from_address":"coinexxxxxxxxxxxxx","to_address":"coinexyyyyyy","amount":[{"denom":"cet","amount":"100000000"}],"unlock_time":"0"}}],"fee":{"amount":[{"denom":"cet","amount":"4000000"}],"gas":"200000"},"signatures":null,"memo":""}}'.encode('utf-8')
print('to_sign', unsigned_tx_bytes)
bz = sign(key_name.encode('utf-8'), secret.encode('utf-8'), unsigned_tx_bytes, chain_id.encode('utf-8'),
          'block'.encode('utf-8'), int(account_number), int(sequence))
print('signed', bz)

[ngugcx]

It works OK on Ubuntu 18.04.