u/Epicjunper47

So I recently bought a used m3 pro Mac off eBay, and upon setting it up it shows the screen mirroring icon which seems to be lit up no matter what. It always says it's connected to something even though the HDMI port is empty. Turning off wifi/ bluetooth does nothing and starting it in safe mode also doesn't get rid of it. Ive also factory reset it but the icon is still there. Anyone know what this could be?