Help! Indelible windshield smudge, tried everything

Firstly, I have read and learned very much from this site. Thank you to all of the contributors over the years. I have searched everywhere for help and have tried everything I have found. Now I am posting to see if there is anything else I can do.

I have a non-oem windshield that was replaced a few months ago. Within the past month, I did a full detail on my car (nanoskin,polish,wax) and cleaned the interior. I now seem to have a very faint smudge smack dab in front of me on my windshield. I *believe* it is on the inside of the windshield but cannot be 100% certain. There appears to be no other marks like this anywhere else on the car or on the windows. I am not certain when exactly the smudge arrived or how it got there or what it is. I am convinced it happened in the past month, and is not a windshield defect that went unnoticed for 3+ months.

Some back story, I was struggling to clean my windows effectively. I was using meguiar's perfect clarity glass cleaner. I stopped using it and went back to windex because it was too difficult to buff off the oily/greasy residue and always left tremendous streaking on my windows.

Now I am back to using windex and am satisfied with my progress. However, now that my window is truly clean I can see this smudge.

Things I've tried; I have tried a razor blade, goo gone, rubbing alcohol, and windex, all separately, and did not combine any 2 of these things. It appears that I cannot even get the smudge to change shape, I seem to have zero effect on it whatsoever. I am reluctant to use steel wool on my interior windshield. I am not sure where the manufacturer's film is on the windshield; inside or embedded.

I have been unable to get a camera to focus on the smudge. It is very light and faint, and if it were anywhere else on my car I would ignore it, but it is directly in front of my line of site. I am stumped. Please provide any thoughts, ideas, or things to try, thank you so much.

I cannot feel the smudge, it's perfectly smooth. It's hard for me to accept that it was a glass defect but that is starting to make more sense any other theories. I'll contact the glass shop and try a little more and see where that gets me. I'll follow up here.

Thanks scuff

You guys have convinced me it's a lamination issue, thanks for the responses everyone. klix58, same thing w/ me, it is invisible in certain light, and easy to spot in other light. The responses here, combined with getting no impact out of the razor blade convinced me. I'll be calling the glass shop today or tomorrow. 2013 vw jetta gli 70k miles is in the shop getting an intake manifold replaced under warranty and a decarb : /

I called the shop and once I mentioned it was delamination they didn't hesitate to replace it. No inspection necessary, getting it replaced Thursday. Thanks again for the responses you guys and the community here are legend. I'll be reading.