I see that it is a part from the Synth Field Helmet (Fallout 4).
I looked at it in my slicer "layer by layer" and in my modeling program and I don't see an issue.
It looks like it was created all in one piece and not grouped.
I wonder if the yellowing of the part in the image is the 18% issue?
I see part _12 is the other side and does it have the same issue?
View attachment 836087