Groupby transforms

I plot multiple box traces automatically by grouping like below:

  const fcbox = {
    y: values,
    type: "box",
    showlegend: false,
    transforms: [
      {
        type: "groupby",
        groups: gvalues
      }
    ]
  };

The values in gvalues are numeric. I was expecting the boxes are ordered and placed in the x-axis using their numerical value. But, they are treated as if they are categorical.

However, If I had not used the transform and manually grouped and created the many box traces myself (with name set to the numerical value) and supplied them as data to the plot, it would place them nicely on the x-axis based on their numerical value. How can I get it working with the groupby transform?