ComboBox with on_hover_text and on_disabled_hover_text

[hydra]

I'm failing to make 'hover text' (aka tooltip) appear when hovering over a combo box that is created inside an add_enabled_ui closure.

let have_selection = self.selection.is_some();
let have_phases = !self.phases.is_empty();

ui.add_enabled_ui(have_phases, |ui|{
    egui::ComboBox::from_id_salt(ui.id().with("phase_selection"))
        .selected_text(match &self.selected_phase {
            Some(phase) => format!("{}", phase),
            None => tr!("form-common-choice-phase"),
        })
        .show_ui(ui, |ui| {
            for phase in &self.phases {
                if ui
                    .add(egui::Button::selectable(
                        matches!(&self.selected_phase, Some(selection) if selection.eq(&phase.phase_reference)),
                        format!("{}", phase.phase_reference),
                    ))
                    .clicked()
                {
                    self.component
                        .sender
                        .send(PlacementsTabUiCommand::PhaseChanged(phase.phase_reference.clone()))
                        .expect("sent");
                }
            }
        });
})
    .response
        // FIXME the `on_hover_text` does not work, no tooltip appears when hovering over an ENABLED combobox.
        //       the `on_disabled_hover_text` DOES work though.
        .on_hover_text(if have_selection {
            tr!("project-placements-tab-phase-hover-text-with-selection")
        } else {
            tr!("project-placements-tab-phase-hover-text-no-selection")
        })
        .on_disabled_hover_text(tr!("project-placements-tab-phase-hover-text-no-phases"));

As per the FIXME in the code above, when the combo box is ENABLED, NO hover text appears when hovering over the widget.

Video:

Recording.2025-09-18.171843.mp4

What am I doing wrong, or is it broken?