Problem plotting heatmapgl subplots


I would like to plot several big heatmaps with Plotly.js and the performances of “heatmapgl” are better than the performances of “heatmap”.
The issue is that I cannot plot “heatmapgl” subplots whereas it works with “heatmap”.

This is a simple example of my problem:
(It works if you replace “heatmapgl” by “heatmap” in data[0].type and data[1].type or if you plot only one heatmapgl.)

Can you help me please ?

Thanks in advance.

More Details:

This is the detailed error message I get:

Uncaught TypeError: Cannot read property ‘x’ of undefined
at handlePositionDefaults (plotly-latest.js:127420)
at Object.supplyLayoutDefaults (plotly-latest.js:127205)
at Object.exports.supplyLayoutDefaults (plotly-latest.js:133299)
at Object.plots.supplyLayoutModuleDefaults (plotly-latest.js:140100)
at Object.plots.supplyDefaults (plotly-latest.js:138929)
at Object.plot (plotly-latest.js:112517)
at Object.newPlot (plotly-latest.js:113020)
at test_heatmapgl.html:33

The issue seems to be due to the fact that grid._axisMap is not instantiated because the function that should do it - contentDefaults(layoutIn, LayoutOut) - is not called.
Indeed, this function is called only if layoutOut._has(‘cartesian’) is true but the basePlotModule is “gl2d”.