flip_conv_id empty

[notpushkin]

Here's my simple handler class:

class Handler:
    async def __call__(self, bot, event):
        if event.msg.content.type_name == chat1.MessageTypeStrings.FLIP.value:
            print(event.msg.content, flush=1)

And this is what it prints out (formatting my own):

MsgContent(type_name='flip',
    text=None,
    attachment=None,
    edit=None,
    reaction=None,
    delete=None,
    metadata=None,
    headline=None,
    attachment_uploaded=None,
    system=None,
    send_payment=None,
    request_payment=None,
    unfurl=None,
    flip=MsgFlipContent(
        text='gqF2AaJ2MYKkYm9keYKmcmV2ZWFsgqNjY2jEIKTHVHrHQJtd85tM4MELrONjgBXuaB3PsIIdgRZcA7ddpnNlY3JldMQgduj/lmQiq2dmbcWCXJIzSjD9f6HXVb9YANbGbuC26VShdASibWSDrmNvbnZlcnNhdGlvbklExCAAAD3GsBhtlbdws7qRZMGtu622IrxZ4oI1kcznobh57qZnYW1lSUTEDHppaPupROHnFP9A8Klpbml0aWF0b3KCoWTEEH+L21NwNBEjt89tNLzmoBihdcQQlWMS5SCyN0fr1Ncg52mqAA==',
        game_id='7a6968fba944e1e714ff40f0',
        flip_conv_id='',
        user_mentions=None,
        team_mentions=None
    )
)

Note that flip_conv_id is an empty string here, thus we're unable to properly call loadflip later. It is however available in API directly (i. e. when calling keybase chat api-listen, it appears as intended). Any idea how to deal with that?