The issue with the pages not indexing is not rare, but as I told you try to be patient and use the Google's API which is the most trustworthy right now for self-owned sites
About ranking, is not rare either, specially if many people in the forum is suggesting that your content is mostly copied, it will never rank, in fact it may appear in the "similar results sections" which is outside the SERPs.
This even happened to one of my sites which was being "copied" by big newspapers (as press releases) and the NP contents were putting my own site news in the "similar results section" which was really obnoxious.
Try to create original content and see how it goes. I understand that if you are copying is because you are willing to go wild (+10K copied pages at least). Otherwise, it doesn't make any sense, and you should not matter much about specific ranks but ranks as a whole for long tail keywords that don't even appear in GSC (you need another software to check this, like GA, or preferably, Matomo)