exoplanet transit: diagram doesn't match the red phase line in the plot

[sstoneb]

I am using the exoplanet transit simulation as seen at this url: https://ccnmtl.github.io/astro-simulations/exoplanet-transit-simulator/

There seems to be a misalignment between the location of the planet in the diagram and the location of the vertical red line on the light curve plot. I loaded the simulation fresh, and simply used my mouse to drag the red line. You can see the issue below.

In this first image, the flux has already started to drop but the planet hasn't yet made first contact with the stellar disk:

In the next image, the flux is still flat (at its minimum) but the planet has already started to exit the stellar disk.

The problem persists even when the inclination is set manually to 90 degrees, as seen in this third image where I've placed the planet at first contact and the flux has already decreased halfway to the bottom of the dip: