Boot into TWRP (Hold Volume Up + Power). Go to Wipe > Advanced Wipe . Wipe: Dalvik, Cache, System, Vendor, Data. Do not wipe Internal Storage.
EMUI is notorious for aggressive RAM management. It kills background apps to save battery, often missing notifications. Custom ROMs like LineageOS offer a lightweight interface, freeing up the 4GB of RAM for the apps you actually use. huawei y9 prime custom rom
The Y9 Prime's defining feature is its motorized camera. Boot into TWRP (Hold Volume Up + Power)
Here is the critical warning. Unlike Xiaomi or OnePlus, Huawei locked down bootloader unlocking in mid-2018. The Y9 Prime (2019) falls into the "dark era." Advanced Wipe . Wipe: Dalvik
A lesser-known gem. DerpFest offers a "smooth" experience with built-in QS panel mods and a very active Telegram community for the STK-LX1.