[Freeswitch-users] FS not sending me BYE when channel hangup

Hello ) 2nd day fighting with issue, not able to find it's source. We developed 2 SIP apps - for Android and IOS (using PJSIP) For Android all fine :) For IOS - when remote party hangs up - FS does not send BYE message. There must be something I'm missing, when doing either INVIE or else - but I can't find any serious difference between Android and IOS invites. Maybe someone have a clue, how it's possible to ask FS to not send BYE?