UA 6185 then UA 3754 at Houston
Savannah → Houston → Waco
Timetable, Houston time
15:35UA 6185 from Savannah at the gate
11:30UA 3754 to Waco leaves the gate
19 h 55 apart on the timetable, overnight
UA 3754 leaves 19 h 55 after UA 6185 arrives on the timetable: more than half a day, so not a connection we count.