GPU AMD Radeon(TM) RX 560
AMD FX(tm)-6300 Six-Core Processor 3.50 GHz
8BG RAM
64 bit
I somewhat fixed this issue before, with lowering sound to 16bit 41Hz, going dx9, putting sound to character 100 and lowering ambience. There still was stuttering, but only very very rarely. For example I did lvl 83 trial, and I think the sound stuttered only twice. However, this means the audio in game is VERY POOR. This is not a fix in my eyes.

Let me preface that I restarted my sound setting to normal (so 24bit, 48hz) and my sound setting for FFXIV is the same as the main sound settings (so the input and output for my speakers are the same), and I'm playing on DX11, with nothing in background being on. I am trying to see if the advice Square put up works.

I logged in, and the first thing was stutter sound in the INN ROOM while doing nothing. I switched to dancer, did a few aoes and it got bad. Switched to whm and spammed a few holies and heals - that did nothing.
I went outside the inn room in Sharlyan and was met with more stuttering. That's fine, its loading, whatever. I tried the first fix. Putting the settings to standard desktop. Stuff seems ok, nothing major, ran around the market board and nothing happened.

Dungeons I did with these settings:
1. Battle of the Bridge as a WHM. Stutter a few times, but solid. My sound effects are around 50 and still there are the boss sound effects that just overpower everything.
2. Alexander 4 - absolutely nothing, again sound effects from bosses are loud for some reason. I am not sure if it's because the position of listening is on character 100.
3. Went to an area in Endwalker, and just stood next to a quest. I hear some crackling, but nothing major. I attack a mob as a bard and immediately it starts. Switched to WHM and its not as bad. Attack again as a dancer a mob and its back again. I put the game on High priority, but nothing majorly changed. Weird. Staying in one place doing nothing also gives audio stutters.
4. I get The Aery and try something. I lower the audio listening to camera to about 30%. Immediate audio stutter on mobs. Put it back up to 100 and its fine. After the first boss the audio stutter starts again and its on and off. Not too often. One example: During Niddhog fight, when the attack Sable Price was finished, the sound effect was really loud, more than any other audio and it stuttered. At this point I try to reduce the number of characters and objects being shown, but you can guess it does nothing.
5. In Paglth'an I get stutters on first two major pulls as an astrologian, first boss is alright, the big pulls after first boss nothing happens and same with second boss. Moment the tank gets the mobs after second boss it starts to stutter. I move my camera as that helps sometimes, and notice if I keep my camera on the background and not on the mobs it completely stops. The rest of the dungeons is without problems.

I am utterly baffled as what is happening. I know my PC is old, but never have I had these problems in any of the expansions.

went to dx9, high priority, lowered to 16bit41hz. - still stutter while standing and killing mobs but severely reduced
WOD - small stutter when joining ,small sutters around the sound effects, but bgm is good, atomos - small sutter with bgm too, small audio stutter while standing before the last boss doing NOTHING.

I know I went to too much detail, but I have really really no idea what to do other than having the audio be utterly bad, which is not a fix SE. I am tired. So I hope this at least helps.