Hi Jose,
Did you check if there is any unexpected database growth. If i suppose the DB you are using is Oracle, could you please check if the tablespaces are having sufficient free space. Also, are the DB cleanup jobs running fine in DB13.
Also please check if some huge logs are getting generated in the system, which might lead to slowness. Also check if the load balancing is working fine in SMLG, and there are sufficient work-process in accordance with the number of CPUs.