EM auto task causes slow database

These two days the customer complained that the database was slow, looked at performance, and found nothing unusual.
View job found a content of
Emd_maintenance. Execute_em_dbms_job_procs
performed particularly frequently.
Use
EXEC Dbms_job. Broken (job#,true);
EXEC Dbms_job. REMOVE (Job);
cannot be removed successfully.
Last use:
EXEC sysman.emd_maintenance.remove_em_dbms_jobs
Successful removal, note that a commit is added at the end;

EM auto task causes slow database