Hyperv 2008R2 - SQL server failover cluster VM backup nic keeps losing network connection

Hi Guys,

Issue:
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Hyperv 2008R2 - SQL server failover cluster VM backup NIC keeps losing network connection

- from Active node both management and backup nic working fine
- however from passive node management working fine but backup nic keeps losing network connection


so far we tried patch level comparison, cluster validation and add/remove NIC card, virtual IP and assign different IPs but issue still same.