FB 851 then BA 962 at Heathrow
Sofia → London → Hamburg
Timetable, London time
12:10FB 851 from Sofia at the gate
06:45BA 962 to Hamburg leaves the gate
18 h 35 apart on the timetable, overnight
BA 962 leaves 18 h 35 after FB 851 arrives on the timetable: more than half a day, so not a connection we count.