FR 3929 then FR 8231 at Barcelona
Trieste → Barcelona → London Stansted
Timetable, Barcelona time
10:50FR 3929 from Trieste at the gate
06:20FR 8231 to London Stansted leaves the gate
19 h 30 apart on the timetable, overnight
FR 8231 leaves 19 h 30 after FR 3929 arrives on the timetable: more than half a day, so not a connection we count.