Symptoms:
Network Extension tunnels go down after a NE tunnel was removed from a different appliance. Large number of HCX related packet drops are seen on the active NSX Edge. NSX Edge HA state will show unstable (standby Edge will be continuously in sync-standby).
This issue is a result of TX hangs on the ESXi host. As a result there is a loss in HCX traffic across the active edge.
This issue is resolved in SDDC version 1.18v7. If upgrade is not an option Please open a Support Request with VMware support.