So, in the Japanese Forums, they suggested we tried the LatencyMon software to detect latency issues for audio.
My result turned out bad, as seen in the image below.

How is everyone else's result?
To check, open LatencyMon, click the green start button, wait at least 5-10 minutes, and if it gets Green, it means it's good, black means not so good, red means bad.

If you get a green result, try then running the scan while playing FFXIV to see if results change.