We can select different styles for mobile, desktop.
Not selecting different styles as expected
If Styles for desktop, mobile not selected as expected, it might be due to a cache issue. the cache(cache plugin, servers side cache) creates only one static file per page and the same page loading for desktop, mobile.
There are two ways we can fix this issue:
Method 1: If there is an option to enable to detect devices on cache plugins installed on your website, enable it.
Method 2: Go to customize in our plugin and enable check this only, if styles for mobile, desktop not selected as excepted.