Below is the code for territory assignment rules.. code is working fine in personal org and facing issues in sandbox. Please help..
global class runTerritoryAssignmentRules

{   @future(Callout=True) 
   webService static void fireTerritoryManagementViaSoap(list<id> nd) 
    { 
      list<account> act= [select id from account where id=:nd];
       list<account> lstAccountToUpdate= new list<account>();
       for(account t: act){
          // t.check_for_this__c= false;
           lstAccountToUpdate.add(t);
       } 
              partnerSoapSforceCom.Soap obj = new partnerSoapSforceCom.Soap();
        partnerSoapSforceCom.LoginResult loginResult = obj.login('XXXXXusername,password);   
        obj.SessionHeader = new partnerSoapSforceCom.SessionHeader_element();
        obj.endpoint_x =loginResult.ServerUrl;
        obj.Sessionheader.sessionid = loginResult.sessionid;
        system.debug('@@@@ssessionid'+obj.Sessionheader.sessionid);
        List<sobjectPartnerSoapSforceCom.sObject_x> lst = new List<sobjectPartnerSoapSforceCom.sObject_x>();
        for(Account ac:lstAccountToUpdate)
        {
            sobjectPartnerSoapSforceCom.sObject_x tmpObj = new sobjectPartnerSoapSforceCom.sObject_x();
            tmpObj.type_x = 'Account';
            tmpObj.Id = ac.Id;
            lst.add(tmpObj);
                    system.debug('@@@@lst'+tmpobj);

        }
        partnerSoapSforceCom.AssignmentRuleHeader_element  obj1 = new partnerSoapSforceCom.AssignmentRuleHeader_element();
        obj1.useDefaultRule = true;
        obj.AssignmentRuleHeader = obj1;
        
        partnerSoapSforceCom.SaveResult[] lst1 =obj.update_x(lst);
    } 
}