FB 851 then BA 770 at Heathrow
Sofia → London → Oslo
Timetable, London time
12:10FB 851 from Sofia at the gate
10:20BA 770 to Oslo leaves the gate
22 h 10 apart on the timetable, overnight
BA 770 leaves 22 h 10 after FB 851 arrives on the timetable: more than half a day, so not a connection we count.