Dynamic batching stops when I disable "cast shadow"

Hi All

I have a question on a mechanic I don't understand why happens.

Basically, I have a utility that spaws a lot of prefabs. These are placed on the scene, and initially I had both cast and receive shadows enabled on the prefab. But, after a while I no longer need to cast shadows, so I disabled that.

However, disabling "cast shadows" makes my "Saved by batching" draw calls plummet from 5k to 3 (simple scene).

Is this expected?

Thanks all

/Henrik