iphone 视屏video播放的时候，点击转发按钮，video瞬间黑屏，转发截屏黑色，设置的imageUrl无效。请问一下什么情况？

视屏源格式如下：

http://gslbmgspvod.miguvideo.com/depository_sp/asset/zhengshi/5100/177/582/5100177582/media/5100177582_5003429943_55.mp4.m3u8?msisdn=18221632216&mdspid=&spid=600058&netType=0&sid=5500238100&pid=2028597139&timestamp=20180807141157&Channel_ID=&ProgramID=638052878&ParentNodeID=-99&assertID=5500238100&client_ip=58.247.126.66&SecurityKey=20180807141157&promotionId=&mvid=5100177582&mcid=1000&mpid=130000023434&encrypt=23920ffa2ed5c95df96765c8121f446c