"We're seeing league system processing delays of 10-20 minutes right now. This means that:
1. Your LP changes, series wins/losses, and promotions/demotions might not show up until ~20 minutes after your game finishes. They will still be processed eventually.
2. You might see the LP change from a previous game displayed on the stats screen. This is just a display error and doesn't mean that you've lost LP from a win. You will still gain LP from the win, it just might be delayed.
In the short term we're working on fixing the issues that are causing the processing lag, and in the slightly longer term we're working on fixing the client issue that can cause an earlier message to be displayed.
Thanks for your patience while we work to get this fixed!"