One thing that gets overlooked is the HDMI handshake. Power everything off at the wall for a minute, then power up TV first, then console, then the bar. Make sure CEC is on only where you need it and confirm the TV actually selected ARC or eARC as the audio output. Use a certified high speed HDMI cable on the ARC run.
On the TV disable any audio processing like equalizers or clarity features, set audio to Passthrough on the console input, and keep lip sync adjustments at zero to start. On the soundbar pick the plainest sound mode. After that, if audio still lags, add a bit of video delay on the TV for the console input only.
