Very short callback after attended transfer

We made update Asterisk to version 13 (by installing from ports in FreeBSD 10.2). And the problem with attended transfer appeared. When a client calls, secretary answers the call and tries to transfer it to manager. If the manager does not answer, the call returns back to the secretary but the phone rings one second (maybe less) and then the call enters the standby phase. The secretary does not have time to pick up the phone! The second time (if the mananer does not answer again) the call returns back normally. So each firs attempt of callback is unsuccessful. In Asterisk 11 it was all right.
How can I fix it?
This is my features.conf file:

[general]
pickupexten = *
xfersound = beep
xferfailsound = beep2
atxfernoanswertimeout = 10
atxferdropcall = no
atxfercallbackretries = 2
atxferloopdelay = 5
[featuremap]
blindxfer =>
atxfer => #