Intermittent shader issue in CK and game

[Furiant]

Recently (past couple of days) I've been getting this graphical glitch with certain models, namely fire/ember MSTTs and Redoran lanterns. On the fire model it looks like this:

I use MO2. I've never had this issue before; it just started yesterday. It happens only occasionally. It may appear like this in CK, or in game, or both.

Any idea what could be going on here?