ts片段在seekTime之后无法下载的bug

[niuxinhuai]

设备： 在iOS14.4.2下和iOS12.1.4下百分百复现，而在15.1上没有复现
复现步骤
1.创建player

• (void)avPlayerDemo1 {
  NSString *url = DEMO_URL_HLS;
  NSURL *URL = [NSURL URLWithString:url];
  NSURL *playbackUrl =[SJMediaCacheServer.shared playbackURLWithURL:URL];
  self.avPlayer = [AVPlayer playerWithURL:playbackUrl];
  self.avPlayerLayer = [AVPlayerLayer playerLayerWithPlayer:self.avPlayer];
  self.avPlayerLayer.frame = self.view.bounds;
  [self.view.layer addSublayer:self.avPlayerLayer];
  [self addObservers:self.avPlayer.currentItem];
  }

• (void)addObservers:(AVPlayerItem*)item {
  [item addObserver:self
  forKeyPath:@"loadedTimeRanges"
  options:NSKeyValueObservingOptionInitial | NSKeyValueObservingOptionNew
  context:nil];
  [item addObserver:self
  forKeyPath:@"status"
  options:NSKeyValueObservingOptionInitial | NSKeyValueObservingOptionNew
  context:nil];
  }

• (void)observeValueForKeyPath:(NSString*)path
  ofObject:(id)object
  change:(NSDictionary*)change
  context:(void*)context {

  if ([path isEqualToString:@"status"]) {
  AVPlayerItem* item = (AVPlayerItem*)object;
  switch (item.status) {
  case AVPlayerItemStatusFailed:
  // [UIView showToast:@"视频播放出错啦~"];
  break;
  case AVPlayerItemStatusUnknown:
  // NSLog(@">>>>>>>>>>>>>>>>>>视频未知状态");
  break;
  case AVPlayerItemStatusReadyToPlay:
  // NSLog(@">>>>>>>>>>>>>>视频已经准备好播放了duration:%lld",self.duration);
  [self.avPlayer play];
  [self.avPlayer seekToTime:CMTimeMake(30000, self.avPlayer.currentItem.asset.duration.timescale)];

      break;
  }
  

  }
  }

当前代码运行起来，就会发现，在低版本中会出现ts片段下载失败的问题，导致界面假死现象。请问这个应该如何解决