I think it depends on which version of FD you're using -- I'm certainly not a pro -- just got here myself...
But, unless you're on premium, you have to "hit the add button" in two places.
If you ate a kiwi, first you search for it. When you find it, you set the amount you ate and click the first add button -- the "+" mark. Then you're taken yo a confirmation page of sorts and you'll see the "add" button -- click it again and it SHOULD be logged.
If it's not logged, something is going wrong but it's pretty tough to determine what that something is without being able to actually see what's happening. One possibility that rolls across my mind is to make sure you're on the right day. (But that might not matter since, even if you're on the wrong day, it should get logged to whatever day you're on...)
Keep playing with it...
Eat this today! (If you don't like that one, come back and click again...)
My Calorie Intake Goal:
Keep the tank full and feel good!
Next physical challenge:
Ride my bicycle from Seattle to SanFran!
Stand at the high point
of every State in the US -- one down (#4 on the list), 49 to go!