4G High Erab drop

Hello expert
I’m a newbie in 4G optimization. Currently i’m working on the main cause of Erab drop. I’ve checked and found it’s as a result of MMe inducing this. While troubleshooting further, i checked for any alarm but no issue, checked ressource congestion, S1 link and X1 link but still no issue. Please can someone provide other things to investigate further on this main cause of this high erab drop? And incase it can be due to coverage or quality, what are the main kpi’s and counters to check for that.Vendor is ericsson. Thanks in advance

pmErabRelAbnormalEnbAct – ERAB Releases by ENB

pmErabRelAbnormalMMEAct – ERAB Releases by MME

pmErabRelAbnormalEnbActCdt - due to down time

pmErabRelAbnormalEnbActUeLost - due to UE lost

pmErabRelAbnormalEnbActHpr - due to HO prep stage

pmErabRelAbnormalEnbActHo - due to HO exe stage

pmErabRelAbnormalEnbActTnFail - due to S1, X2 down or transport unavailability

pmErabRelAbnormalEnbActPe - due to pre-emption