After updating, perform a "Wipe Cache Partition" from the recovery menu to ensure the phone runs smoothly without old system files clashing with the new update.
Usually, major OS updates hurt battery life initially, but ColorOS 12 is optimized well for the A9 2020’s 5000mAh battery. oppo a9 2020 coloros 12 update
As of my latest knowledge, the has not received an official update to ColorOS 12 (based on Android 12). After updating, perform a "Wipe Cache Partition" from
0;1052;0;2cb; 0;d7;0;f1; 0;88;0;98; 0;279;0;17a; 0;1159;0;b19; oppo a9 2020 coloros 12 update