While I am a premium user, I am very disappointed by the PDF annotation features.I use the apple pencil and the whole experience is really bad. Many times I annotate the PDF with my hand by mistake, the response is really slow and the most disturbing, when the screen goes off, I lose all my annotations (even if I open immediately the evernote app).
The only reliable solution is to export the PDF to PDF Expert and then copy back to Evernote after I finished the annotation. Please find a way to fix these issues.