Hi AG,
Can you confirm if both the vmnic (which you described as active-active) is connected to a same physical switch or to different physical switches.
Please check advanced performance tab for network and check if any packet drops happened in past day.
If connected to same physical switch, you should be using ether channel for active-active setup.
If connected to different physical switches, you should be using active-standby configuration (in vswitch) unless your network is not configured for Primary/Secondary or Active/Standby configuration. Kindly consult with your network admin reg the same.
Also if you are using active-active, the best load balancing would be to choose route based on ip hash.