I am a bit puzzled with this now that I had carefully prepared my "papers" I am stuck again

When I look in the flights there is a route KATL - MPTO with a B738 which has also been flown in the past (same config) by Bruno. So I prepared my papers for this long flight.
Now, when I load Flight Logger I choose that departure and destination and get several flights listed, I chose the one of the main division (EHM-4800). However, I see there that in spite of it showing in the history as flown several times on a B737, on FL I can only choose Fokker 70 or some other plane but not the B738

I can't make that flight then on "my" Boeing?
On a secondary note, A Boeing 737-800 is commonly used in real life for that route, even a Boeing 767 so I wonder why it is a Class 4 flight with a Fokker 70? In real life I have flown this route several times, sometimes with stopover in Miami. Just wondering...
And... on a tertiary note... why are many flights shown in Flight Logger with 00:00 as both arrival and departure times? seems to be a common ocurrance on flights on the Americas.
If not I guess I will have to search another interesting flight. Want to know though...