After seaching on high HO due to DL interference, I found this disscussion very interesting. We are having the same problem in our network.
we have tried BCCH re-planning,even tunning from hopping to fix frequencies but with no results 🙁
Maybe we have incompatibility of DTX and AMR as disscused,,, we have these features activated.
If anyone has find a solution of high HO due to DL interference,,, please share it with us.