How to keep playing live in low latency hls?

Hi:
I use Exoplayer 2.18.1's demo app to test low latency hls live stream. I met a problem. Normally, it always play the latest segment and the latency is short. However, the latency will
increase in some situations. I don't understand what happend?(for example: networks problems and the video freeze temporarily and continue later). I need to use seek bar to seek to the last position to keep playing live. Is there any to keep playing live always?