Precapture on the Z8 and Z9 is jpeg only (C15, C30, C60, C120) and will override your normal setting to use raw. The precapture default is jpeg standard, although after the most recent firmware, you can now change it to jpeg fine (with a very cryptic menu).
Is it possible that you used precapture and left it in precapture? I've done that a couple of times and try to remember to change back to my base settings after I use it.
Is it possible that you used precapture and left it in precapture? I've done that a couple of times and try to remember to change back to my base settings after I use it.