They do attack though rarely while the nest is disabled, but they seem to stay near the nest during that time. and do not spread out and search for targets.
when there is only 1 enemy in range and the nest is upgraded with 2 dragons, only one dragon will attack it. https://streamable.com/xrfkg (On cocos, both dragons keep attacking the target alternately. https://streamable.com/bvs6t)
On cocos, the dragons act the same whether the Grootlang disables their nest or not. They just search for targets in range and freeze them. On love,