Earlier today, a hotfix was issued to fix the bug plaguing the new Competitive Play mode in Overwatch, where competitive games played on Control maps were not affecting skill ratings.

Via Lylirra on the Blizzard forums:

Last week, several players reported that wins and losses on Control maps (Ilios, Lijiang Tower, and Nepal) during Competitive Play were not correctly influencing Skill Ratings. The exact problem causing this to happen was identified early this morning, and we were able to develop a fix shortly after. That fix has now been implemented on PC and Xbox One in all gameplay regions (and will be in place when Competitive Play goes live on PlayStation 4).

Our sincere apologies for any inconvenience, but thank you so much for your reports and helping us making Overwatch a better game!