Hello! I'm sorry to hear about the issue with your POCO M3 Pro being stuck on the loading screen. It seems like you've already tried a hard reboot using the volume down and power keys without success. Since you're concerned about losing your data and don't want to reset your phone, here are a few more steps you can try:
1. Safe Mode: You can try booting your phone into safe mode to see if the issue is caused by a third-party app. To do this, press and hold the power button until the power off menu appears on the screen. Then press and hold the "Power off" option on the screen until you see the option to reboot in safe mode. This will disable all third-party apps temporarily. If your phone boots up successfully in safe mode, you can try uninstalling recently installed apps that may be causing the issue.
2. Clear Cache Partition: Boot your phone into recovery mode by pressing and holding the volume up and power keys together. From there, look for an option to "Wipe Cache Partition" and select it. This will clear the cache files on your phone which may be causing the loading screen issue.
3. Factory Reset Without Losing Data: Some phones have an option to reset settings without deleting data. This option may vary depending on the phone model. Look for "Reset settings" or "Reset app preferences" in your phone settings. This will reset system settings but should keep your data intact.
If none of these steps work and your phone is still stuck on the loading screen, it may be necessary to consider a factory reset as a last resort. Remember to back up your data if possible before proceeding with a reset. If you have any important data on your phone, it's always a good idea to regularly back it up to prevent any loss in situations like this.
PH