As per the title, the auto update simply doesn't auto update, last tested in 1.1.8. During my flights when I have auto update turned on and then manually update a good while later, I usually get a newer ATIS that the auto update didn't detect for whatever reason, making the auto update feature quite useless.
PS: Friendly reminder about my other thread, regarding the lack of the green auto update symbol on the D-ATIS page: