When you fail a map, you can either retry, quit playing the map and play another one, or watch the failed replay using the F1 key. There should be an option to be added in the options menu that lets you automatically retry the map when you fail it. The name of this option is "Auto retry when failed". When this feature gets added, you don't have to click the retry button, so the game automatically retries the map for you if you fail. By default, this is disabled and you can enable it if you want.