This is the way it works:
1- When you power on your laptop, if your battery is above 95%. you will get the message "plugged but not charging"
2- When you power on your laptop, if your battery is under 95%, you will see the message "Plugged and charging" until the battery charge reaches 100% (not 95%). That's why sometimes, even if you see that your battery is at 97% and charging also, that means before starting your laptop, the battery was under 95% and reaches 97% since then.
Update: so now its back up to 100% and when I unplugged again it says 100% remaining.