Thanks for the answer. But it looks like a system bug. Back button changes it's color while navigation bar has the background. It cannot be expected behavior. Also Customizing your app’s navigation bar does not provide any information about customizing navigation's bar background. At the moment we cannot remove custom background from the application, because it is what user is used to for the last 5 years. Clients will not be satisfied with such changes. Are there any plans to fix it? Or any workarounds to overcome the issue?

@DTS Engineer Hello. Please check my previous comment.