FR 6597 then BA 1369 at Manchester
Barcelona → Manchester → London Heathrow
Timetable, Manchester time
19:50FR 6597 from Barcelona at the gate
15:10BA 1369 to London Heathrow leaves the gate
19 h 20 apart on the timetable, overnight
BA 1369 leaves 19 h 20 after FR 6597 arrives on the timetable: more than half a day, so not a connection we count.