When a load balancer is configured with session affinity timeout set (options:affinity_timeout=x), northd generates logical flows use action "learn()" to generate flows that contain mapping between the client and the backend that was selected.

When the backend is removed from the load balancer config, the learnt flows corresponding to that backend should be removed.

That is currently not happening because the original "learn()" action does NOT set the correct cookie in the learnt flows.

https://github.com/ovn-org/ovn/blob/b187e038d70e511d74897587b84a59d3a06e6788/lib/actions.c#L5002-L5007