screen_coords_to_world_pos and SSAA

[gdaviet]

I am having trouble getting screen_coords_to_world_pos to work with SSAA on:

import numpy as np
import polyscope as ps
import polyscope.imgui as psim


pos = np.array([[-1, 0, 0], [1, 0, 0], [0, 1, 0]])
vtx = [[0, 1, 2]]

ps.init()
ps.register_surface_mesh("tri", pos, vtx)
ps.set_ground_plane_mode("none")

def callback():
    io = psim.GetIO()

    screen_coords = io.MousePos
    world_pos = ps.screen_coords_to_world_position(screen_coords)

    if np.all(np.isfinite(world_pos)):
        psim.TextUnformatted("Hover!")

#ps.set_SSAA_factor(4)

ps.set_user_callback(callback)
ps.show()

Without SSAA, the above runs fine, the label correctly appears when the mouse hovers the triangle. This is no longer the case when the line #ps.set_SSAA_factor(4) is uncommented (or enabled in UI).

Is there a transformation that needs to be applied to the screen_coords with SSAA enabled?
Incidentally, picking seems to work fine, as in the native "Selection" box shows the correct info when clicking on the triangle.