Oppo A9 2020 Rollback Package Exclusive Page

Attempting to use unofficial rollback packages or third-party flashing tools may void your warranty or permanently "brick" the device. Software Support Status

However, OPPO will no longer develop Android 10 security patches. Only use this rollback if you plan to keep the phone as a secondary device or if you accept the security trade-off for performance. oppo a9 2020 rollback package exclusive

No. Using an official rollback package does not void your warranty. However, if you brick the phone using a third-party tool like SP Flash Tool, that will void it. Our method uses stock recovery only. oppo a9 2020 rollback package exclusive