LH 231 then 4Y 900 at Frankfurt
Rome → Frankfurt am Main → Dubrovnik
Timetable, Frankfurt am Main time
11:50LH 231 from Rome at the gate
09:254Y 900 to Dubrovnik leaves the gate
21 h 35 apart on the timetable, overnight
4Y 900 leaves 21 h 35 after LH 231 arrives on the timetable: more than half a day, so not a connection we count.