In order to provide a consistent environment across devices, Android needs to adjust the DPI to a standard (ldpi, mdpi, ...xxhdpi). That's why Android doesn't really use every possible DPI.
In the case you would like to simulate a custom device, please check the real density used by android for this physical device and create a custom virtual device (See Samsung / Google / Huawei / Xiaomi device is not available in the template list).
For more details about screen support in android, please refer to this article.