Help, my D string all buzzy + sitar like (out of nowhere)

constantine

This is a stumper (at least for me ). Out of nowhere, on my Dell Arte Hommage the D string frets 9-12 now produce some nasty buzzy sitar like tone when playing gently or aggressively. Like it might sound if the action way too low (currently > 3.0mm at Low E). It wasn't there 2 weeks ago. I have tried different strings and higher action, same result. Could those frets have worn down suggesting the need for a fret level? The neck relief looks good, I tried some minor adjustments but no difference.

Jazzaferri

Sounds to me like moisture change over time has subtly changed the shape of maybe the neck or the way the neck sits. It may resolve itself if the RH goes back to where it was?

My Dunn has a very low action and can get a tiny bit buzzy when the moisture content changes but so far it has always worked itself out in a few days once things get back.

Duozona

Could also be a lifted fret, have a close look at one fret higher than where the buzz is, so 13th fret if the buzz is between 9-12th fret.