to solve this problem follow the following steps:
Stop the nmleth process manually.
Modify bRelocateAlarmByTrailAssociate from 0 to 1 in U2000server\nml\nmleth\conf\cfg\nmleth.cfg
Restart the nmleth process.
Browse current alarms about the faulty trail again.
Alarms are relocated and relationship between the trail and its alarms will be updated. As a result, alarm status is synchronized.