Assumptions (reasonable defaults)
Ensure you flashed a ROM specifically built for your device variant. Restoring your stock NVRAM backup via TWRP usually resolves cellular network drops.
The custom ROM landscape for the Oppo A83 is not as vast as for some other phones, but there are definitely exciting paths to explore.
The setup screen was buttery smooth. No stutter. No lag. He connected to Wi-Fi—it worked. He made a test call—the earpiece crackled but worked. The flashlight did, in fact, turn on when he shook the phone, but that was a quirk he could live with.
Custom ROMs offer a solution to several common frustrations: What is an Android Custom ROM?
Swipe to confirm the flash. Wait for the process to complete.
Your (e.g., getting the newest Android version, maximizing gaming speed, or maximizing battery life)