How to set a custom DPI with Genymotion Desktop?
Android needs to adjust the DPI to a standard (ldpi, mdpi,...xxhdpi) in order to provide a consistent environment across devices. Android does not really use every possible DPI.
To simulate a custom device, check the real density used by Android for this physical device. Edit the virtual device display settings to match the real density. edit the virtual device display settings
For more details about screen support in Android, please refer to this article.