tasklist not work after integrate keycloak with jbpm

I try to integrate keycloak sso, it's work.
I logging into "business-central" how I expect. If I try to list the processes instance, the system give me the right result... whether I do with "bussine-central" or with "REST" service... but when I try to list the tasks instance the system give me a empty list... maybe there is some problem with "realm"?