A backward compatibility issue exists between Access Manager 7.1 (all patch levels) and the amclientsdk.jar bundled with the policy agent 2.2 Hotpatch 5 and 7.
Workaround. If Access Manager 7.1 does not have cookie hijacking prevention enabled, add the following property to the policy agent AMAgent.properties file:
com.sun.identity.enableUniqueSSOTokenCookie=false
Note: If Access Manager 7.1 does have cookie hijacking prevention enabled, this workaround will not work.