The parameter is not listed on the Results tab as having differences, but it is listed in the sync script. There are different sections to the sync script, depending on how the parameter can be modified. If the parameter cannot be found in the first section, which could be run in the Editor to change the parameter value, look under the “These parameters differ, but can't be changed by ALTER SYSTEM commands” and the “Change these parameters in <schema1> to match <schema2>” sections to see if it is there.