Some elements in custom theme doesn't work on mobile app

[AKN]

 In this variable input object I've removed second row ("Kur Hariç") using css in custom theme.

#HhQPpV_content > div > div > select > option:nth-child(2) {
    display: none;
}

it now look like this in browser, which is what I need:

However, using mobile Qlik Sense Client-Managed app, this option still appears. I am using same app on both browser and mobile.

Also I have another problem with mobile app. I'm setting background-image of an object. It works perfectly on browser but when we look at the mobile app, the image doesn't appear.

How can I solve this problem?