PDF wont render properly

Hy, I use the app to review PDFs from my classes in University.
This problem only appears on iPad and only in this PDF app.

When I use the apple engine to render the pdf, it looses 90% of the text and just shows single letters without any sense.

When I use the Marginnote Engine, it looses some words?? I was so confused to see everything work nicely on my MacBook but seeing it beeing so broken on the iPad…

Again, i tested it in 4 other apps on the iPad, it worked everywhere expect Marginnote.
I also copied the PDF, created a new one etc still didn‘t help.
How can this be an issue? What should I do? I already paid for the app so i want to use it, but with this issue this seems not possible atm… Hope this will be fixed.

Cheers

I also have 2 screenshots:
1st: Marginnote engine: there is a word missing, also single letters in the pdf just dissapeared. Also top left, instead of „E“ there should be „Ein“.


2nd: Apple Engine, you see whats wrong lmao

PS. it happened also in white mode!

If it helps to get to the root of the problem, converting the pdf to jpeg and back to pdf fixed the issue, i guess its a problem with non-flattened pdfs?

But this killed the option to annotate and mark in the pdf, so please fix this issue.