event_data("plotly_hover") not triggering for full range of 3D surface

I have a 3D space comprising four surfaces added as traces using add_surface. I hope to link these to a subplot using event_data("plotly_hover") (or event_data("plotly_click") ).

These events trigger correctly over some of the range of the surface, between x = 15 and 38 inclusive, but not the full range.

A more detailed description of the problem, including screengrabs showing event_data() working correctly and incorrectly, is provided here, along with a reproducible code example.

The desired use case for this feature is shown in the last two tabs of the app deployed here. The aim is in effect to perform 'tomography' on the surfaces along the age (x), year (y) and birth cohort axes (y-x). Within the range over which event_data triggers correctly this works really well.

Start with the reproducible code example in the linked Stack Overflow question and compare event_data("plotly_hover") and event_data("plotly_click") across the full add_surface range. Done means the events trigger consistently across all four 3D surfaces and the full x range, including values outside x = 15–38.