U2 2323 then FR 4545 at Barcelona
London Luton → Barcelona → Porto
Timetable, Barcelona time
20:10U2 2323 from London Luton at the gate
19:15FR 4545 to Porto leaves the gate
23 h 05 apart on the timetable, overnight
FR 4545 leaves 23 h 05 after U2 2323 arrives on the timetable: more than half a day, so not a connection we count.