Unwanted circular reflection in render

Hi I’m quite new to this community, sorry if my description isn’t good enough!

so I’ve made a render of an optical disc which I textured procedurally. I rendered an animation of the disc rotating along the z axis and weirdly, a circular reflection appears in one of the frames (see image).
It seems like a reflection as the circle moves around if I rotate around the viewport, but it doesn’t seem to be a reflection of another object, because I have tried hiding other objects (such as lighting) and the circle remains.
I’ve checked neighbouring frames and although the circle doesn’t appear in the render, it is visible at some angles in the viewport.

Any ideas as to what the artefact could be?? Thanks!