PTP synchronization in ConnectX-5

We are noticing that in long running network experiments with ConnectX-5, PTP goes out of sync, even though we have isolated the PTP process from the experiment process (no CPU contention), and isolated the PTP traffic from the experiment traffic by using two different interfaces on ConnectX-5.

Has anyone noticed similar issues, and if so is there any way we can isolate PTP so it does not go out of sync? We do not notice this issue when we are only running PTP on our network (no other data traffic).

Could you share an additional details about what kind of the software you are using for PTP, how it is configured, the logs that shows the issue? Do you use Mellanox OFED drivers? What is the version?