afgncaap Yes, they should work. They do on my device. Have you waited between updates? In my experience, the Play Store doesn't update apps as soon as it can for some reason. Sometimes it takes a couple days after it detects an update before it goes through with the installation.
Note that for auto updates to work, Play Store also has to be the designated installer for a given app, meaning the current version of that app on your device must have been installed through Play Store. You can check this in the info page of your apps in settings.
Edit: I don't receive notifications about updates either, even though they work.