League players are gaining low LP due to “internal changes to ranked system” in preparation for new season, Riot says. The LP gains should normalize after playing a few games.

What affects how much lp you get?

LP is determined based on your Matchmaking Rating, or MMR for short. Its a hidden number that represents a players skill, to some more familiar as Elo. This number is different from your actual ranking. Riot uses it as a way to determine how much LP you should gain or lose.