I just reset my system and the rotation lock square was there. It looks like all the drivers are in the Chipset section. Beside the chipset drivers, you certainly need the Intel integrated Sensor driver is important and maybe the Intel Serial IO driver.
If you think you have all the drivers, you might try uninstalling one of those and reinstalling. Other than that, I don't know what is wrong. It may be your sensors are not functioning. The Sensor driver is the original one and will not update, as you know.
I have no more suggestions .. but I will look for older threads since I remember a couple a few months ago.
Well, the Integrated sensor is in the System Devices in the device manager. If you right click and select uninstall, it should uninstall. Then try loading the one you download from Dell.
I just tried installing that driver again and it still says it installs but the version does not change.
I wish I knew what was wrong with your system but you might want to open a service report with them. Your system seems to do everything except know when you are changing its orientation.
There is also a separate section titled Sensors, which seems to use the Win 10 drivers, whatever they are for.
As long as it isn't working and while waiting for Support, you might pretend it is a steering wheel and keep turning it to different positions. Maybe it would unlock the part of the sensors which senses rotation and orientation.