The dialog advance on the interact key works in general (multi-page NPCs do advance to the next page). Mai closing instead of advancing points at her specific dialogue data, which I am checking. If you spot other NPCs doing the same, naming them helps me sweep.

Thanks Drew. We checked Mai's lines and they match the original, so her conversation isn't meant to end early. We found a likely cause: on smaller game windows (or touchscreens) a single Space press can count twice, skipping past her second window and closing it before you see it. A fix for that is being made now. To help us confirm it's the same thing you saw: were you playing in a smaller browser window, or on a touchscreen laptop or tablet? And if you click OK with the mouse instead, do you see both of her windows?

This is fixed and live now. We confirmed it: on smaller game windows the game also turns on its touch controls, and a single Space press was being counted twice, which closed Mai's second window before you could see it. Now one Space press always advances exactly one window, and tapping the on-screen TALK button still works. Refresh the game once to get the update, and reply here if Space still skips a window for you.