Why do frame times spike during Banishers group combat?

During intense combat, frame times spiked to 45ms, causing noticeable stuttering. I tried disabling the camera in Device Manager, but it killed my streaming setup. I used GamePP Conflict Detector to set Razer Synapse to manual start and enabled hardware encoding in OBS. RivaTuner confirmed frame times stabilized at 7-12ms, and Task Manager showed CPU usage holding steady at 65-72%.