BA 841 then BA 748 at Heathrow
Dubrovnik → London → Geneva
Timetable, London time
14:15BA 841 from Dubrovnik at the gate
17:55BA 748 to Geneva leaves the gate
3 h 40 apart on the timetable
The last days
BA 841 and BA 748 weren’t both flown 15 min to 12 h apart in the last 21 days.
Statistics from past flights, not live flight information. Always check times and your connection with your airline, and don’t base travel or booking decisions on these numbers.