What is the new FSD button when navigating in the Tesla map?

[SuperPigDots]

Since the update yesterday, I have noticed a new FSD-looking button that can be pressed (completely blue) or un-pressed (only the roadway drawing on the button is blue). It appears at the bottom of the route options when routes are navigating in the Tesla map (it is just near to the add-a-stop-on-the-route button). The update did not describe this button and pressing it doesn't either. I also notice no difference at all when it is pressed or depressed. I Googled and came up with nothing. What the heck does it do???

 

[Ravire]

It’s the toggle for navigate on autopilot from the legacy autopilot stack.

 

[SuperPigDots]

It’s the toggle for navigate on autopilot from the legacy autopilot stack.

Yeah, it appw as red suddenly then went away after a a day or two. How strange.