It has been a while since I first asked this question; I know! I had to back-up 100 gb of data and prove that data and that took a while.
The issue still exists; I want you to know, with the Portrait Orientation Lock button turned on or off it makes no noticable difference; and, after the update there was no noticable difference.
I may have discovered a few things that make the difference. I will not be sure if any of these procedures, to be mentioned next, have a benefit; and, I will not know for sure until I conduct further tests. I take a lot of pictures with the iPhone for my work; and, as I continue to take pictures I will learn more.
I need you to know that the pictures may rotate without any observable connection to any iPhone settings or iPhone state. I state, "may rotate"; because, sometimes everything is going as expected for a time and then all of a sudden there is the undesired rotation of the pictures in storage when retrieved for viewing. When retrieving the pictures for viewing and there is the undesired rotation, it has been observed that the thumbnail image, on the "camera ready to take a picture screen", will rotate whether or not the lock screen is active. This happens when I take a picture in the horizontal reference and then bring the camera up to my face so I can view it which turns the camera orientation vertical.
In addition, I have tried to keep the camera horizontal and place it flat on the surface of the horizontal back-drop with mixed results. I have to assume that at times I fail to keep the camera level in the horizontal position until I have placed it on the surface flat. If you ever notice that the Portrait Orientation unlocked is precarious enough and that this precarious balancing act can cause difficulty then you might be able to understand what I am getting at. Again, what I am getting at, is at times when the undesired rotation occurs; while, I have tried to keep the camera flat. I may have failed to do so within the tolerance of the Portrait Orientation gizmo.
So, from all this, if you ask me I say there is no ability to lock the image storage orientation while the image is being written to drive. If the camera tilts out of absolute level from the horizontal position then the pictures will display as rotated from that desired, the orientation when the picture was taken. If the iPhone is already out of level when the picture is taken then the image will be written to storage as rotated. This last sentence needs more testing to prove.
Once the pictures have been written to drive then there is no connection between the image in storage and the frame of reference to the observer rotating from the desired orientation when the picture was taken. I am sure it is what others have been referring to when asking similar question.
In the last three paragraphs I tried to outline what I see as the main reason for this issue I am asking about. In addition to that main statement I made for the failure of the images to remain as the photographer wishes there are two more observations I have made.
One: I have had a series of success over failure when the camera is charged above 65%.
Two: When the picture is of the back of a card or poster, something that contains little detail or even little color variation there is a much harder time getting the images to remain in the desired position.
One note on the questions already asked on this topic, I do not recall anyone who asked this question reply to their post about their experience going forward. I can think there is a lot of "Move On and seek another source" attitude until the ability to devote time in which to resolve this issue no longer seems important; and, that most move from dealing with this issue in other ways such as rotating the images back to the desired orientation in the editor.
I do not have this luxury; I take way too many pictures to spend that amount of time fixing something that should not be broken.
Ok, thanks for you answer and your time.