When you request access via enterprise role it will give entitlements associated with that role to the end user. Issue when trying to remove the role access sometime it remove the role but doesn't remove end user group membership in the target system. The request will create task with No Action Required.
To resolve this issue make sure to turn on Create Dependent Entitlement Task for Remove Access in the endpoint.
Steps to resolve the issue:
So go to Identity Repository then Security Systems then look for the your security system then associated endpoint then in the endpoint go to Endpoint Details down in that page look for "Create Dependent Entitlement Task for Remove Access" and turn it on.
