Changing three settings can make the car feel different. It also leaves you guessing which setting helped. Start with a saved baseline and a problem that keeps showing up at a specific point in the lap.
Describe what the car is doing
Use the sim’s baseline or track preset if it has one. Save a copy, put in several clean laps, and make a note of where the problem happens. For example, the car may drift wide as you pick up the throttle in a long corner. Check the replay first. A late turn-in or early throttle application can create the same symptom, and you can practice those without touching the setup.
Compare the same part of the run
In a session that allows setup changes, use the car manual or garage help to choose a single adjustment relevant to the issue. Make a small change and save it separately with a name you can recognize. Keep the starting fuel, tire state, track conditions, and warm-up routine as close as the sim allows.
Look at several clean laps. Did the car hold the line with less steering? Did the change make a different corner harder? Compare the spread in times and what the car does in that corner before deciding. A single quick lap might have more to do with your line than your adjustment.
Load the baseline for one more short run if the difference is unclear. Keep a brief record of the setting, the corner, and what you felt. It gives you somewhere to start the next time that problem comes up.