Input lag is easier to investigate when you describe the delay precisely. Does a local button press feel late, does the picture stutter, or does only an online match behave badly? Start with that distinction instead of applying every performance tweak you find.
Separate the possible layers
NVIDIA distinguishes network latency from system latency and breaks local system delay into peripheral, computer, and display contributions. Use those categories to organize your observations, not to diagnose a component from a single symptom. How To Reduce Lag: A Guide To Better System Latency
If the game offers a comparable offline mode, note whether the same delayed response is present there. Keep the controller, display, and game settings unchanged for the comparison. An offline result is a clue, not proof of where an online fault lies.
Inspect the display's documented gaming settings
Samsung describes Game Mode as changing video processing to reduce input lag. Availability and controls depend on the television model, so use the instructions for the exact device rather than copying a menu path from another screen. How to play games on a Samsung Smart TV
Record the original picture settings before testing a supported gaming mode. Repeat the same action and compare both responsiveness and picture quality. Keep any setting only if its result and tradeoff are acceptable.
Avoid unrelated fixes
Do not reset accounts, open network ports, or replace a controller merely because a match felt slow. Collect the game and device versions, the affected mode, and the test results for the relevant support team.
This is a troubleshooting sequence, not a promise of competitive advantage or zero delay. If multiple things changed at once, return to a known configuration before drawing a conclusion about which adjustment mattered.