Why are there two Asr times and is one preferable to pray over the other?

When the angel Jibreel came to teach the Prophet Muhammad the different Salah times, one time he came slightly earlier for Asr and another time he came slightly later. Both hadiths collected by Imam Timrithi, both are authentic. This is just some of the reasons why there are two different Asr times, because one day he came earlier and one day he came slightly later. Both views are valid. The majority go with the first view of the earlier Asr Salah time. The Hanafi Matab goes with the slightly later view. Both of them I said are valid. The issue is flexible, so whichever you are more comfortable with or whichever Matab you follow, no issue with either of them.