I have noticed that older movies which have black bars along the sizes (to give a square picture. Like 4:3 ratio) don't show any lights at all for the sides.
On your website autofill black bars is an advertised feature. It would be disappointing to discover if it was for top and bottom black bars only and not the sides too.
There are a lot of older movies and TV shows that are 4:3.
Even the example in the video below from rocky horror has very thin black bars on the sides and it still gives 0 light feedback.

Any comparison video clips for better reference?
I just swapped out the version one box. It worked fine and the version 2 box does not.
My 2.0 is not filling in black bars on 16:9 content on Apple TV. The top and bottom change to solid red while the sides display the correct colors. I’ve reset the box 3 times as well as reset the appletv.
My 2.0 unit is not filling in black bars on 16:9 content from a Fire TV Stick. (Not Max)
Dear,
For the black bars refill, the R&D team considers that the source of the movie is either 21:9 or 16:9 ratio. For the 4:3 ratio black bars refill, I have submitted the problem to our R&D team to figure out if it could be fixed. But I suggest you could adjust the media size setting for it.
(Only the black bars refill algorithm is added on the top and bottom sides)
As the attached video showed.