I have tried changing the graphics settings and the resolution. Max, High or Low I still saw this issue. I've also tried full screen and windowed instead of borderless windowed. I do remember one setting, I think it was Shadow Softening, that did affect this but added even worse glitches.
It's most visible with characters wearing white clothing. E.g. Asahi, Ryne, the PC wearing White Mage gear, etc. It's also most visible in certain cutscenes, but I have seen it outside of cutscenes as well. I first really noticed this in the last cutscene for the quest "Storm on the Horizon" and rewatched the beginning multiple times with various settings to test that out. There's this flickering shadow border on Asahi's collar during that scene. I did record a clip of that but I don't see any way to upload that file to this forum. I also noticed it on my character in the area you are dropped into right before "The Seat of Sacrifice" trial during "Hope's Confluence" it was most noticeable when facing the pillars of light and with the camera zoomed in close, while wearing the WHM lvl 80 artifact gear body piece. You could also see it on his bare chest, but not on darker clothing pieces.
I recently replaced my CPU (plus motherboard and RAM) but am using the same graphics card as before. The graphics card driver has also had updates fairly frequently. I think Windows has forced a couple of updates in that time too.