UA 5946 then UA 3754 at Houston
San Luis Potosi → Houston → Waco
Timetable, Houston time
14:53UA 5946 from San Luis Potosi at the gate
11:30UA 3754 to Waco leaves the gate
20 h 37 apart on the timetable, overnight
UA 3754 leaves 20 h 37 after UA 5946 arrives on the timetable: more than half a day, so not a connection we count.