I'm sorry for my bad English.
A year ago, a version of windows 10
When it was before 19xx, the extended display was functional.
(You could move the square icons on 1 and 2 and use a second desktop anywhere you wanted, left, right, up or down.)
But it's not recognized now.
I'm connected to the iphone version.
The only thing that works is the mirror.
(Sorry for the Japanese image.)
I'm currently using the windows 10 20H2 version.
I have an NVIDIA GTX1070 on board (same as a year ago).
If you can determine the cause of the problem, please do so.