It could be your sculpt LOD Factor as well depends on how close or far away you are and will sometimes glitch.
I know how to do it in the LL viewer but not the others (anyone else can help?)
Go to prefs and advanced - check mark show advanced menu. Once this is done the advanced menu will show up in your menu bar on top of the viewer.
Click on Advanced -> Show Debug Settings
Type in RenderVolumeLODFactor
Set it to 4 and hit enter. This should fix any glitches that may come up due to this setting
.