Cloudy glass on print head

I noticed this last week but just got around to taking a picture to post it:

That cloudiness in the left window seems permanent. I don’t know if it’s always been there (only got my GF Pro last month) or not, but it’s been there at least the past week. It’s on the inside, and taking a Zeiss wipe to it does nothing. And it doesn’t seem to be related to humidity or anything, my GF is indoors in an air conditioned room and I don’t keep the vent hose hooked up to anything when not in use, so the machine is not exposed to the outside air.

Everything works 100% fine right now, including “set focus” / auto focus. All other glass including the lens looks perfect, so I don’t think it’s related to any material I cut, which is mostly just PG draftboard/wood/acrylic.

Just wondering what’s going on here? Anyone seen this before?

Can’t say if it’d cause you a problem or not. I hope it’s fine!

But I can tell you I can’t look at this picture anymore because my OCD is in overdrive begging me to disassemble the head just to clean that off.