FB 437 then EN 394 at Frankfurt
Sofia → Frankfurt am Main → Luxembourg
Timetable, Frankfurt am Main time
13:15FB 437 from Sofia at the gate
12:55EN 394 to Luxembourg leaves the gate
23 h 40 apart on the timetable, overnight
EN 394 leaves 23 h 40 after FB 437 arrives on the timetable: more than half a day, so not a connection we count.