We are observing SRVCC failure from LTE to UTRAN and after that UE is re-establishing to LTE. We have around 70% this kind of case in SRVCC failure.

Can anybody help to find out the reason? This is happening in good 3G Radio condition. 

After UE gets Handover Command to UTRAN message in downlink, It is not sending Handover to UTRAN complete in uplink. 

We have checked this in multiple locations and in different radio conditions We are getting this kind of failures in almost all cases.