Many contain malware or corrupted files. Here are trusted sources:
Yes, but you must use SP Flash Tool with Format All + Download . Downgrading may cause sensor issues; proceed with caution. Oppo A83-A83T Global Firmware
No. Bootloader unlock is separate and not officially supported by Oppo for the A83. Unlocking requires third-party tools and voids warranty. Many contain malware or corrupted files
This comprehensive guide covers everything you need to know about the firmware for these specific models, including the difference between variants, where to find the files, and how to flash them safely. including the difference between variants