recently I implemented Google Analytics UserID Tracking Code. First everything seemed to be fine and registered users showed up at the new view I created. But today I had a deeper look on the analytics and noticed, that the daily and weekly view are showing different results. Here are some images to proof:
As you can see in the red marked areas Google Analytics shows different data for the 19. September. Also you can see that on the daily view Google Analytics show more users than sessions which also seems to be very wrong.
I'm quite sure the issue appeared for the first time when I implemented the GA User Tracking Code. Something I could imagine what's happening is, that a user visits the page, and gets registered by Google. A moment later, when his user data is loaded the set userID event is sent to GA and the user is registered a second time.
On the other hand there is a setting available on GA which should prevent exactly this behavior, here is a pic from Google Analytics:
Does anyone know what is causing this problem and how to fix it, or am I missing something?