Just copying my response here: The 5 win 15 loss system doesn’t preventing your true rank from changing all it does is just prevent you from being able to see it changing accurately until those thresholds are met. Assuming your win-loss ratio is exactly 1, your rank shouldn’t change. Rank adjustment is purely based on wins and losses and not individual performance so if you are winning more than you are losing, then you should climb ranks and vice versa. Leaving games counts as an automatic loss. However, it might also be a bug that prevents your rank from adjusting, which there is currently not a solution for. Linking my post in case you would like to read more about this issue:
Comprehensive Thread Of All Top 500/Competitive Bugs. I put your thread under: Incorrect Rank Adjustment. Any help in spreading the word about this thread would be greatly appreciated.