When you broadcast a live video to any streaming platform, a minimum lag or time delay, also known as latency, is inevitable. A normal delay is usually between 10-15 seconds, and this doubles as a safety precaution to allow the event producer or moderator to cut the video stream should something go wrong during the live event.
The length of this time delay depends on various factors, like internet connection and bandwidth, and it can vary from viewer to viewer.
If you're curious to learn more about how latency works, consider the following flow:
Source: https://docs.mux.com/guides/video/reduce-live-stream-latency
When you consider the steps above, each one has the potential to slow down the next step, or get backed up by the previous step. The more latency you can tolerate, the safer the system is, and the lower probability you have for an unhappy viewer. If any step gets backed up momentarily, the whole system has a chance to catch up before an interruption can be observed in the playback. And when everything is running smoothly, the player has extra time to download your content's higher-quality version.