Zero Inter frequency handover attempts in 3G

Hello Experts,
Post addition of dual carrier single sectors in 3G sites, there are zero IFHO attempts ( 3G-3G). After enabling IFHOcauseCPICHEcNo and IFHOcauseCPICHrscp at RNC level, IFHO attempts started coming. But still in some of the RNC’s attempts are zero.

Please suggest what to be checked and enabled at RNC / WBTS / WCEL level
(Nokia System)