Cause: NetworkManager event script was restarting the iscsi.service to start sessions configured for automatic startup when new network interfaces came online. But restart was actually tearing down and recreating already active sessions, and races would occur when multiple network interfaces came online in a short period of time, resulting in multiple sessions for a single target configuration.
Consequence: Multiple iSCSI session to the same target portal via a single interface were sometimes created.
Fix: The NetworkManager event script was changes to use a new reload target of the iscsi.service, which will make attempt to being up sessions that don't exists but will not tear down existing sessions.
Result: iSCSI sessions configured for automatic startup should become active once the network is ready, without duplicate sessions.