调用身份证识别接口，别的身份证调用没问题，唯独一个身份证有问题。返回  {"log_id":3181735119045034775,"words_result":{"姓名":{"words":"栗颖","location":{"top":25,"left":65,"width":30,"height":13}},"民族":{"words":"汉","location":{"top":48,"left":128,"width":9,"height":10}},"住址":{"words":"辽宁省法库县丁家房镇湾柳街村三组46","location":{"top":92,"left":61,"width":130,"height":31}},"公民身份号码":{"words":"","location":{"top":0,"left":0,"width":0,"height":0}},"出生":{"words":"19791130","location":{"top":66,"left":59,"width":103,"height":15}},"性别":{"words":"女","location":{"top":48,"left":64,"width":9,"height":12}}},"risk_type":"normal","words_result_num":6,"image_status":"unknown"}  。识别出来内容，但状态返回 unknown。是什么原因，身份证有问题？是假的？