Well that may be happening
1. First could be that the IPTV links list that you are using to stream channels is having a server side lagging error. So you better change your list.
2 Second, could be the the legacy version of the VLC media player that your are using. Update you media player and try again running the links
I hope that helps
Sorry, i didn't knew that an english version is also availbale for this post.