The issue was caused by the calling .getMaxInactiveTime() to set the value of @private long maxInactivityTime = getMaxInactiveTime(); in ConnectionManager. However in case of S2SConnectionManager@, when it was constructed with default constructor it called @.super() so the tigase.server.xmppserver.S2SConnectionManager#getMaxInactiveTime got called returning private variable maxInactivityTime in S2SConnectionManager before it's value was correctly initialised.