FR 2437 then FR 5997 at Madrid
Rome → Madrid → London Stansted
Timetable, Madrid time
09:00FR 2437 from Rome at the gate
21:25FR 5997 to London Stansted leaves the gate
12 h 25 apart on the timetable
FR 5997 leaves 12 h 25 after FR 2437 arrives on the timetable: more than half a day, so not a connection we count.