The problem of not lighting up or displaying a small pop-up when a call arrives is familiar to many users of MIUI shells and the new HyperOS. Instead of the usual full-screen interface, you see only a tiny banner in the corner of the display that is easy to miss, especially if the phone is on the table with the screen upwards. This is not only inconvenient, but also leads to missed important conversations, which causes irritation and time loss.
There are many reasons for this behavior, from the banal settings of the permissions of the Phone application to conflicts with energy saving or third-party design themes. Often, after a firmware update, the parameters are reset or the algorithms of the interface are changed, which requires manual adjustment. In this article, we will discuss all possible ways to return a full call interface that covers the entire screen and attracts attention.
We will look at both standard menu customization methods and deeper system options available through an engineering menu or special applications. Understanding how the notification system works in conjunction with telephony will help you not only solve the current problem, but also correctly customize the device to your needs in the future.
The main reasons for the lack of full-screen mode
Before we get into action, we need to understand why the call interface is not standard. Most of the time, the problem is with the settings of the caller app itself, which can be set to a minimalist display mode by default. Android allows applications to run in the background with limited interface functionality so as not to interfere with the user, but for calls this is critical.
Another common reason is aggressive energy saving: Xiaomi shells are famous for their hard-to-optimize background processes. If the system feels that the Phone app is consuming too much resources or is not working properly, it may limit its ability to display images on a locked screen, a security mechanism that sometimes works too hard.
Also, consider the impact of the design themes and fonts you have installed. Third-party visual packages often change the system files that control the lock screen and incoming calls. If you recently changed the theme or updated it, and the problem appeared immediately after that, then the reason is likely to be a conflict of visual elements.
⚠️ Warning: Installing themes from unverified sources can not only cause the call screen to disappear, but also cause the device to cyclically reboot.
The call app should have the highest priority of displaying on top of other windows. If the privacy settings have accidentally disabled this setting or trimmed with another application (for example, an antivirus or a cleaner), a full screen will not appear.
Configure permissions of the Phone application
The first and most logical step is to check the basic permissions. Android system strictly controls which applications can overlap the content on the screen. To correctly work the call, you need to manually check whether the feature is activated “Master on top of other applications.” Without this permission, the system will block the full screen mode in favor of the window that is open at the moment.
To make changes, go to Settings → Apps → All Apps. Find the Google Phone app or the standard MIUI call (depending on which is set by default). Inside the app menu, select Other Permissions or Permissions, where you want to make sure that all items, especially those related to the screen and notifications, are active.
☑️ Permit verification
Pay special attention to a item that may be called "Pop-ups" or "Floating windows." In some versions of MIUI, this is the parameter that is responsible for whether the call will turn on the full screen or remain as a widget. If the slider is turned off, turn it on and restart the device to apply changes.
Also check the notification settings inside the app itself. Go to Settings → Notifications and Status bar → Notification management. Find the phone app and make sure that High or Urgent is prioritized for Incoming Calls, and you allow screening on a locked screen, which ensures that the system doesn't hide the curtain call.
Adjustment of energy saving parameters
Aggressive battery optimization is a frequent enemy of stable telephony, and if the system decides that the caller app is not actively used, it can put the caller app to sleep, causing the interface to be delayed or misrepresented, and to rule this out, add the app to the power saving exception list.
Open the battery settings and find "App Energy Saving" or "Activity Control." In the list, find your call and change your strategy from "Energy Saving" to "No Limits" so that the app can always stay active in the background and instantly deploy the full-screen interface when the signal arrives.
Also, check your auto start settings. The Security app on Xiaomi has a Permissions section» → «Autorun. Make sure the switch opposite the Phone app is activated, which ensures that the call service starts immediately after the device is turned on and is not stopped by the system while it is running.
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If the problem persists after setting up the power saving setting, try clearing the Phone app cache through the Storage menu in the app settings, which will delete temporary files that may have been corrupted.
Importantly, some HyperOS models have introduced the Advanced Memory feature, which can also affect background services, and if you use this feature, try temporarily disabling it for testing, as memory virtualization sometimes causes delays in the response of system processes.
Using hidden settings through the engineering menu
For advanced users who have not been helped by standard methods, there is access to hidden system parameters through an engineering menu, which allows you to manage low-level settings of the telecommunications module, but you need to work very carefully here, because changing the wrong parameters can lead to unstable communication.
To enter the engineering menu, open the Phone app and dial the combination ##6484## (to log in to the app). CIT-Test menus) or use special codes for the engineering mode, which may vary depending on the processor (MediaTek or Qualcomm). Often, to access the interface settings, you need code ##4636##, which opens the test menu.
In the testing menu, select “Phone Information” and you can find settings related to network type and radio behavior. Although there is no direct “full-screen call” setting, resetting the network settings or switching network modes (e.g., from 5G to 4G/LTE) can restart the phone stack and fix the software interface failure.
The dangers of the engineering menu
There is also a command to reset all call settings, which is done via dialing: ##786#. On some devices, this opens the RTN menu where you can reset, but beware: this action can remove system settings and require reauthorizing accounts. Use this method only as a last resort.
Comparison of standard calls: Google vs. MIUI
Xiaomi smartphones can use two types of dialing interface: standard from Google and branded from MIUI. They have different logic and display settings. Understanding the differences will help you choose the most convenient option or correctly configure the current one.
A call from Google (Google Phone) has stricter rules for displaying notifications in newer versions of Android.It often relies on high-importance system notifications. MIUI (MIUI Dialer) is more deeply integrated into the shell, but may conflict with the themes of the design.
| Characteristics | Google Phone | MIUI Phone |
|---|---|---|
| Interface. | Minimalistic, Material Design | Saturated, with themes |
| Recording of conversations | With a warning from the interlocutor | Hidden (depending on the region) |
| Full screen mode | Depends on system notifications | Depends on the subject of the design |
| Blocking spam | Built-in (Google base) | Built-in (MIUI antivirus) |
If you use a Google call but want a MIUI interface (or vice versa), you can install the corresponding app from the GetApps store or Google Play and then assign it to the default app. However, component mixing (MIUI theme + Google call) is most often what causes the part-screen problem.
It is recommended to use a bundle of "native call + native theme" to avoid visual bugs. If you want to customize the appearance, it is better to change only the wallpaper and icons, without affecting the system components of the call interface.
Solving problems with the themes of design
As mentioned earlier, the themes are one of the main culprits behind the disappearance of full-screen mode. Third-party designers often create themes that are not fully adapted to your version of Android or HyperOS. As a result, system windows, including the call, may not display correctly.
To diagnose a problem, temporarily switch to the standard theme "Classic" or "Default"; go to the Topics app, select a profile, and activate the standard dial. If the calls then start to show up again on the full screen, then the problem was in the visual package.
If you don’t like the standard design, try to find an alternative theme from Xiaomi’s top-rated designers, avoid “Beta” themes or ones that haven’t been updated in a long time, and try using only the lock style from another theme, leaving the system elements standard.
⚠️ Warning: Always reboot the device completely after changing the theme. Simply turning on the screen is not enough, as the system resources of the interface are cached when you boot.
In some cases, cleaning the Themes app data helps. Go to Settings → Apps → All Apps → Themes and click Clear → Clear All Data. This will return the theme settings to factory settings and can fix display errors.