Black box overlay in Mail on iOS

No.

I am referring to being able to see a whole screen filled with an e-mail message, then after moving phone through landscape view and back, I see a few lines at the top and the rest of the screen is black except for the bottom row of icons.

Nothing to do with my preference setting for light text on dark background, AFAICT.

sorry, I guess I still was not clear enough with my words or my pictures.

see the yellow square which approximates the area of the black box that is blocking half of the message area? This is the black box I am referring to.

Again, as far as I can see, this has nothing to do with light or dark theme. It is a bug related to flipping back-and-forth between orientations, portrait to landscape and back again in mail iOS app.

But the lack of a replies that seem to understand my admittedly unclear description does suggest that this is something unusual because of a lot of people were seeing this, it would probably already have been fixed.

when giving feedback to Apple, you were limited to a certain number of characters, with no option to include images or recording. I'm hoping that the problem is now clear enough for the smart folks here to understand it, and I have one more question: how would you describe it to give the most effective feedback to Apple in the limited number of characters they allow?

Again, this is very reproducibly an error caused by the shifting positions from portrait to landscape to portrait again.