Grid layout row height

I’m playing around with the grid layout, based on the sample here

In that example if I set the wrapping column to 1, it appears each row is sized based on the size of the node it contains but with my own code each row is the same size and seems to be based on the size of the largest node overall. I’d like the behaviour of the example but I’m not clear on how I’d achieve that. I’m not setting cellSize, could something else affect the row height?

Ah… alignment: go.GridLayout.Location

But that is the default value for GridLayout | GoJS API.

Usually it is needing to set GridLayout | GoJS API to new go.Size(1, 1) that is the problem.