I too am getting this issue. Making a change to the notification bar in the settings fixes it for a few minutes but soon comes back. Seems to happen only in the evening, so seems like some kind of night mode?
I have the same problem since last two updates (7.3.23 and 7.3.30) on my mi5s. Bar is getting dark on home screen and any applications. Theme changing helps just for a while, Wipe Cache and Dalvik doesn't halp, factory reset (with data delete) helps only for while (one or two days).
Does anyone know how to resolve that problem? What's the reason of this issue?
Hi shadowman. The reason is one application that is making this to happen. It use to be an application that ask to be viewed over other applications. It could be radardroid, or other. Try to think about what application you are using that overlays other apps. Do a factory reset and don't install it
If you don't know what application is, try to install only the basic ones. Do a backup with TWRP and install some more. It during a couple of days nothing happens, do a backup again and proceed with another set of 3 or 4 more. This way you will identify it. But it is not a rom problem. It is a incompatibility problem of some apps.