Can anyone help me ID this please?? I'm worried it will start affecting my plant (which is prized in my collection :)). It is soon enough that I could remove leaves that have it, but I'm not sure if it's a parasite or maybe just sun spots (trying to be hopeful).

this plant gets full/direct sun and she's usually very happy. I started noticing the spots once it started getting very hot outside. They tend to be on the lower leaves. The spots are completely flat and cannot be scraped off like insects can. Besides the spots the plant seems to be doing great, she had a lot of pups this year that I recently removed.

Thanks for for the help!!!