FlightRadar24
 

FlightRadar24 is a neet site to look at air traffic but I have noticed one issue. I see an airplane flying hundreds of miles off the east coast DL200 and when I hit the airplane it says it is flying LAX-ATL which is the first segment. The airplane is currently flying from ATL to JNB (South Africa). Any idea why it won't show the actual routing of the aircraft now and not the
previous segment. I noticed this with some other flights.

Perhaps it is a single flight number from LAX to JNB with en route stop at ATL?

Yes it is a single flight number from LAX bu why does it say the airplane is flying LAX-ATL which is the previous segment and not LAX-JNB.

From FlightRadar 24's FAQ page:
"Why is the route information not correct?
The route is not transmitted from the airplane. The route is taken from our database based on the callsign (flight number). Sometimes the pilot types wrong callsign into the transponder, or there is an error in our database. If you think there is an error in our database, you can report correct route data by pressing the button "Report route error" in the aircraft info window."