Matt 24 also deals with those living as in the day of Noah but the unsaved are not caught up into the air to the Lord, nor do the instructions “stay awake and be ready” make any sense if this is referring to the those who are already asleep (spiritually dead) and have never been ready. Read the scripture for what it is saying instead of trying to fit doctrine into the Word.
There are many verses between Matt 24:31 and 25:31, they are parables speaking primarily about the need for readiness at the return of the Lord. Chronologically, there is no indication that the events of Matt 25:31 come long after Matt 24:31. The Matt 24:31 gathering seems to precede the judgment of the nations. On the other hand, the gathering to the Lord mentioned in the clear rapture passages does not say this event is preparatory to the judgment of the sheep and goats or to the start of the kingdom. It could be the prelude to those events, but no passages say it does. And, if not connected with the rapture timing, then it is likely that Matt 24:31 and 1 Thessalonians 4 speak of different times and different events.