Having issue in migrating the permissions using acs commons Acl packager for the second time.

Problem statement - Acl packager updates groups & permissions for the first time in the target server but after modifying permissions for the second time it doesn't effect in the target system.

Tried options :
1) We updated the mode as update , merge in filter.xml file and package with AC handler as merge preserve, merge & overwrite. Nothing worked.

Expecting solution : we need to modify permissions and migrate any number of times to the target system. Please let us know if any one faced this issue and came up with the solution.