Continuous Rebalancing issues

Hi team
We have 4 node cluster and all buckets in Full Ejection mode. We have 40 GB RAM quota allocated for each node . Continue getting “Relabalancing issue” with below logs :
Can you please help what makes the behavior changed ?

“Rebalance failed. See logs for detailed reason. You can try again.”

Rebalance exited with reason {service_rebalance_failed,cbas,
{badmatch,
{error,
{bad_nodes,cbas,get_agent,
[{‘ns_1@tccbadc-cluster-0001.tccbadc-cluster.bi-cb.svc’,
{exit,
{{{case_clause,
{error,
{unknown_error,
<<“failed_to_cancel”>>}}},
[{service_agent,cancel_task,2,
[{file,“src/service_agent.erl”},
{line,474}]},
{service_agent,
‘-cancel_tasks/2-fun-0-’,2,
[{file,“src/service_agent.erl”},
{line,484}]},
{lists,foreach,2,
[{file,“lists.erl”},{line,1323}]},
{service_agent,cleanup_service,1,
[{file,“src/service_agent.erl”},
{line,502}]},
{service_agent,do_handle_connection,2,
[{file,“src/service_agent.erl”},
{line,331}]},
{service_agent,handle_connection,2,
[{file,“src/service_agent.erl”},
{line,308}]},
{service_agent,handle_cast,2,
[{file,“src/service_agent.erl”},
{line,192}]},
{gen_server,handle_msg,5,
[{file,“gen_server.erl”},
{line,604}]}]},
{gen_server,call,
[{‘service_agent-cbas’,
‘ns_1@tccbadc-cluster-0001.tccbadc-cluster.bi-cb.svc’},
get_agent,infinity]}}}}]}}}} hide