Ok try to install the Agent apart, also try to dig if the agent is the cause, sometimes bad drivers make this kind of behavior so also check from the vendor what is adequate for the hardware, reinstall nsxt from each esxi could be an option but is a quick task, so better to verify if the problem is related to drivers or anything else first, take a look on $tail -f /var/log/vmkernel logs to get a better idea.
hope this helps
+vRay
