Why does the system of the Redmi A3x not respond?

For your reference, the various factors can cause this issue as below:
1. The system will become slow or unresponsive when the phone's memory or processor resources are insufficient. This can be due to that there are too many applications running at the same time, or there are some applications taking up too many system resources;
2. System unresponsiveness can be caused by compatibility issues with installed applications or unstable applications;
3. The Android system itself has some errors or issues, such as failed system updates or corrupted system files, causing the system no response.
To resolve this issue, you can try the following methods:
1. Free up system resources by closing some unnecessary applications;
2. Restarting the phone can resolve temporary system issues;
3. You can update or uninstall applications that cause conflicts;
4. Update the system to the latest version.