We have had a couple of instances recently when making network changes that have affected our clusters. This caused a restart on the lead host due to it detecting a network loss and then resulted in system outages. The cluster is configured with dual networks ports in active and passive mode and the understanding was that it would switch if any change or failure was detecetd without producing error events and systems down.
Best answer by sbarab
One other thing, the AHV version should be relatively new (for example AHV-20170830.300 or above 300) as many issues were addressed with the later releases of the AHV.
You can involve nutanix support to review any logs or re-test with them on line (if possible), but I would probably review switch logs and configuration before going that route.