DIAGNOSIS The pointer on the LG Magic Remote is motion-based and requires a clear line of sight to the TV's bottom bezel. Lag is almost always an interference or line-of-sight issue, not a dead remote.
FIX First, replace the batteries. Even if they seem okay, the pointer is sensitive to voltage drops. Next, make sure you're pointing the remote directly at the center-bottom of the TV screen, not at the screen itself. Remove any objects (like a soundbar, game console, or decor) that might be blocking the path. Also, bright sunlight or strong reflective surfaces near the TV can confuse the sensor.
IF THAT DIDN'T WORK Pair the remote again. On the remote, press and hold the Back and Play/Pause buttons together for 5 seconds until the pairing icon appears on the TV screen. This resets the Bluetooth connection, which handles the pointer and voice functions, separate from the IR for basic buttons.
HEADS UP The remote uses both IR (for power/volume) and Bluetooth Low Energy (for pointer/voice). If the pointer is laggy but the power button works instantly, that confirms it's a Bluetooth pairing or signal issue, not a battery problem.