Comment 4 for bug 1650977

I think this bug is related to high resolutions rather that to dual displays but with a dual display setup you have a high resolution setup.
With my LG Ultrawide I also have no Icons when my TV is off and I so just have a one Display setup.
My LG Ultrawide has a resolution of 2560 x 1080 and so with just a single display I also have a higher resolution than a standard HD resolution of 1920 x 1080.
I noticed that Linux Mint sees the resolution as 4480 x 1080 when my TV is also on.
So it just adds the 2 up and says 2560 + 1080 = 4480 and because the dispays are shown beside each other the vertical resolution is 1080.
My guess is that it's all about unhandled high resolutions.

I would be very interested to see what happens if you have a dual display setup with 2 very low resolution screens so a dual display setup would not rise above a resolution of 1920 x 1080.
I would have to see if I can find some old hardware to test this.

Also I would like to know if there is a file that contains the resolutions that are handled.
Maybe then you could edit this file and add your resolution to it and maybe how it should handle the grid for that resolution.
That would be a nice debugging test.