My '16 has a rectangular box warning that says something like Auto Dimming In Process that appears briefly occasionally on start-up.

I believe that it's adjusting the instruments back lighting.

I'm wondering if this is the '21 version of the warning.

 

On a related note... at the very left side of the photo, next to the speedo, there is a vertical six-segment bar that comes up on startup and goes away even before the circle the OP was asking about. Anyone know what this graphic is?

 

That's showing the different views available for that screen display I believe. So if you hit up or down, that six segment bar should return and you will see it change as you cycle through.

 

Just jumped in my truck to confirm and that's 100% correct. Thanks!!

 

Half hour search and I still can not find that post. Has to do with the "odd" spot that appears on the speedometer at start up. Mine showed up.

 

This one?
https://www.f150forum.com/f129/help-...t-icon-505068/

 

No. This is a round, dark circle in the lower left part of the speedometer. Near the zero area.
That post has pictures and many comments about it. Maybe, just maybe it was on the 14 gen site?

 

Is it a symbol of some sort? Or is it more like a graphical error type thing?

 

Your truck thinks you're Quebecois. It is trying to preload the funky circle signs.

 

I think I know which one you mean. I was active in the one I linked and remembered my comment and was easy to search for. Can't think of any keywords aside from "symbol" to search for the one you're thinking of.