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It might be worth you trying to do the following resets:
Enter into your keypad *#7780# and when prompted, enter the default passcode 12345. If you have changed the code, it will be the code you changed it to.
A backup will not be needed as this will not delete any data.
This will erase all data on your device, so a backup is recommended before you do this.
Once backed up, enter *#7370# and when prompted, enter 12345 as the default passcode.
Hope this helps.