MySQL to Oracle Migration

we are using Camunda 7.8.0 with MySQL 5.7.21, we are in process of migrating DB from MySQL to Oracle, and I am able to migrate the DB using SQL Developer with no error/issue but when I am starting application with new connection string (oracle) , getting ENGINE-03005 error on startup.

“Unsatisfied dependency expressed through method ‘processEngine’ parameter 0; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name ‘processEngineFactoryBean’: FactoryBean threw exception on object creation; nested exception is org.camunda.bpm.engine.OptimisticLockingException: ENGINE-03005 Execution of ‘DELETE EventSubscriptionEntity[7c240d0f-a4fd-11ea-a8ed-e285f961a018]’ failed. Entity was updated by another transaction concurrently.”

if someone tried this before and face similar issue please help. or can point out what I am missing.
steps I followed

  1. migrated data from mysql to oracle following the steps in
  2. updated to point to new DB (oracle)