CRS326-24G-2S+IN sporadically not sending PTP follow-up packets

Hi all. First of all, hoping this is the right place to post this query; apologies if not.

I have a microcontroller-based PTP clock authority connected to the switch on ether4; PTP on the switch syncs to that just fine. The switch is in turn acting as a boundary clock to a handful of clock subscriber devices, e.g. another microcontroller-based device on ether10. I’m mirroring egress on ether10 and I can see in Wireshark that while sync messages are reliably being transmitted, roughly 10% of the time follow-up messages are not.

To add some context, I’m developing a PTP-synced networked audio protocol for distributed spatial audio applications. There’s a lot of audio-related traffic activity — roughly 13 Mbps Rx rate, ~1500 Rx packets per second with the version of my system that I’m testing with at the moment. That being said, I’m seeing CPU load no higher than about 6% (in System > Resources).

If anyone has any idea what could be causing the switch to sporadically fail to send follow-ups to its sync messages, I’d be very interested (and grateful) to hear! If I can provide any further details to aid in troubleshooting, please let me know.