UA 3905 then AA 3258 at Houston
Cancún → Houston → Miami
Timetable, Houston time
13:29UA 3905 from Cancún at the gate
09:50AA 3258 to Miami leaves the gate
20 h 21 apart on the timetable, overnight
AA 3258 leaves 20 h 21 after UA 3905 arrives on the timetable: more than half a day, so not a connection we count.