allowedBlocks affecting nested blocks?

I’d like to create a block (parent-block) that will support an innerblock (child-block). Child-block should support inner blocks as well. The parent block should only allow child-block, but child-block should allow any block to be inside it.

If I set parent-block’s allowedBlocks to {[‘child-block’]} then child-block also can only accept child-block as a child. In other words, the parent blocks’ allowedBlocks setting is affect the children as well.

Is this the expected behavior? If so, how do I restrict a parent block with allowedBlocks, but allow the child blocks to have any block as children?