Conversion failed due not receiving signature from one of validators

[jd-swjtu]

1. Test environment, three validators: validator_0: '0x260056e7050afdc2491a343f68b6b10f3302a4a1'; validators_1: '0xf5fea0530dafa59b7a49f2e3539d33d06e7ef6db'; validator_2: '0x064f5cc97da76a83ee28eeb23fab63ad0555ad94'
2. required_signatures = 2
3. We stopped validator_3, since there are 2 of them is running, the conversion still is expected pass
4. Do conversion from DAI to TT-DAI, the transaction is: 0x15282f12f7d56776eec0170e780b707aa8b0b10a0afc8ddc498236ac39706650, corresponding block number is: 12272092
5. After a while, we only get one signature from validator_1, so we checked logs on validator_0. The watcher from block never change, but it got the above Transfer event.

  {"level":30,"time":1563396979704,"msg":"Processing transfer 0x15282f12f7d56776eec0170e780b707aa8b0b10a0afc8ddc498236ac39706650","name":"watcher-erc-erc-affirmation-request","eventTransactionHash":"0x15282f12f7d56776eec0170e780b707aa8b0b10a0afc8ddc498236ac39706650","from":"0x9a78d67096ba0c7c1bcdc0a8742649bc399119c0","value":"10000000000000000000","v":1}
{"level":20,"time":1563396979704,"msg":"Estimate gas","name":"watcher-erc-erc-affirmation-request","eventTransactionHash":"0x15282f12f7d56776eec0170e780b707aa8b0b10a0afc8ddc498236ac39706650","v":1}
{"level":20,"time":1563396979718,"msg":"Gas estimated","name":"watcher-erc-erc-affirmation-request","eventTransactionHash":"0x9d6d384d9e1ec268aeec656b2f7557bc9cac19ee71ee665e187996b6ffbc4b39","gasEstimate":170381,"v":1}

6. On validator_2, we can see the fromBlock is moving forward

{"level":30,"time":1563396846782,"msg":"Getting past events","name":"watcher-erc-erc-affirmation-request","module":"web3","contractAddress":"0xC746DA764aA4093EA1C3e9596F11fb5E04f8Acad","event":"Transfer","fromBlock":"12272085","toBlock":"12272085","v":1}
{"level":30,"time":1563398153901,"msg":"Getting past events","name":"watcher-erc-erc-affirmation-request","module":"web3","contractAddress":"0xC746DA764aA4093EA1C3e9596F11fb5E04f8Acad","event":"Transfer","fromBlock":"12272086","toBlock":"12272410","v":1}
{"level":30,"time":1563398156283,"msg":"Getting past events","name":"watcher-erc-erc-affirmation-request","module":"web3","contractAddress":"0xC746DA764aA4093EA1C3e9596F11fb5E04f8Acad","event":"Transfer","fromBlock":"12272411","toBlock":"12272411","v":1}
{"level":30,"time":1563398160668,"msg":"Getting past events","name":"watcher-erc-erc-affirmation-request","module":"web3","contractAddress":"0xC746DA764aA4093EA1C3e9596F11fb5E04f8Acad","event":"Transfer","fromBlock":"12272412","toBlock":"12272412","v":1}
{"level":30,"time":1563398162310,"msg":"Getting past events","name":"watcher-erc-erc-affirmation-request","module":"web3","contractAddress":"0xC746DA764aA4093EA1C3e9596F11fb5E04f8Acad","event":"Transfer","fromBlock":"12272413","toBlock":"12272413","v":1}

Please help analyze, the log:
affirm.log

[rstormsf]

please show that you have balance difference.
Please record the video with this issue.
https://www.screencastify.com/

I can't reproduce this issue
@jd-swjtu