Huawei 4G low RACH SR with huge attempts/fails L.RA.GrpA.Att/L.RA.GrpB.Att

Dear experts, recently I faced with no LTE service issue on eNodeB which verified with DT. Issue is only one sector/cell. RACH SR is too low approx. between 0-5%. Serving to rural area. No LTE in near 40 KM and village located in 35 km far of antenna direction. Cell radius is 20000. Huge L.RA.GrpA.Att/L.RA.GrpB.Att attempts and fails on cell. Root sequence index replan and cell radius increasing already done and no results. Any suggestion?