Every time I export my video and play it back on QuickTime, the audio begins perfectly in sync to the video as it should. Then when I skip to another part of the video on QuickTime, the audio either gets out of sync or doesn't play at all. This isn't an issue if I play the full video without skipping. The same thing happens when I airdrop the video to my iPhone. The audio plays in sync if I watch the full video, but then if I skip to halfway through the video, the audio either plays completely out of sync, or doesn't play at all. Also when I trim the video on my iPhone to have only a 15 second clip from the full video, there will be no audio in the trimmed clip. This is extremely frustrating. I'm using the same render/export settings I've always used. This only became a problem when I updated premiere to V15.1. Sending the video also plays it back out of sync. I don't understand why this is a problem at all because when I import the exported video back into premiere or onto iMovie, the audio is there and perfectly in sync as it should be. So why does it do this during playback on Mac and iPhone?