Motion Jitter with LinuxCNC + EtherCAT

I’m running LinuxCNC 2.9.4 on a fanless Venoen P12B with a PREEMPT_RT kernel and EtherCAT (IgH master + lcec HAL driver) connected to 5x EL8-EC400(COE) drives via an Intel I225-V NIC using thedriver. Everything initializes correctly—slaves reach OP state, clocks sync, link is stable at 100Mb/s Full Duplex—but I still get intermittent motion jitter, especially after reboot.shows good average latency (~2 µs) but occasional spikes up to 95 µs. I’ve tried kernel parameters likebut that worsened the issue, likely due to the system’s passive cooling. I’d like to keep my current hardware and am looking for any software-based solution to eliminate jitter with thedriver. Any help is greatly appreciated!