Talibans no longer allowing afghans to leave
First they gave 'anmesty' but because people didn't trust that or wanted to leave for other reasons many still wanted out, the talibans are now setting a stop to that stating that they do not want the elite to leave the country.
One very real possibility however is that they also want to be able to take revange against people who earlier opposed them, in that case them first giving 'amnesty' (in an attempt to give them a false sense of security) and then also try to prevent them from leaving would make perfect sense.