EV Switch Prius 2005

I just installed the EV switch from the instructions here in my 2005 Prius. Thunder's installation video was actually helpful eventhough he was installing a different solution. What I noticed was that when he attempted to activate stealth mode after to ICE started, it beeped and gave him a message stating it could not be engaged.

When I do the same, I get the beep and the display switches to the consumption screen, but I never get any message indicating whether or not the mode has switched. If it was unsuccessful, it will beep. If it was successful, it seems to say silent with no indicator.

Is this different behavior because I have a different installation, or is it because I have a 2005 prius? (Im not sure what model they used but Im assuming its a later one)

Thanks in advance.