UA 428 then UA 3755 at Houston
Mexico City → Houston → Lubbock
Timetable, Houston time
10:09UA 428 from Mexico City at the gate
22:10UA 3755 to Lubbock leaves the gate
12 h 01 apart on the timetable
UA 3755 leaves 12 h 01 after UA 428 arrives on the timetable: more than half a day, so not a connection we count.