At this point I get a bit confused - where is that coming from? There is no ether channel configured on any of the nics (at least that's how the physical switches should've been configured). The failover policy is Load Based Teaming. And I start looking at each distributed portgroup - and I find that one of the portgroups is configured with Route based on IP Hash. Found it! I've changed the policy, refreshed the view and the warning disappeared.