I figured that the second or third layer would kind of “iron out” the imperfections, but still strange that it’s occurring nonetheless.

I’ll see spots like this on some of my prints, and that tells me to wash my print sheet, but it’s never in those 45° lines like yours. I wonder if you can feel any texture difference running your fingers over the trouble spots? sometimes you can wear out parts of a textured bed and have smooth spots that are lower than the rest of the bed. It’d be really weird for it to happen in that exact pattern, though.