iPad annotations corrupting PDFs

It is Dec. 2018 and iPad Endnote is still corrupting PDFs!

Even opening a PDF in iPad Endnote is enough for corruption, let alone annotating on it. Today I opened two PDFs on iPad EndNote and both are corrupted and disappeared when I looked on desktop EndNote. I checked inside the EndNote user file and saw that the PDFs appear there but are unopenable, corrupted, no more have a .pdf extention. So I lost many hours that I spent highlighting and annotating those PDFs. In panic, I removed EndNote from my iPad. I am a new user and do not want any more damage.

iPad is a reader and vital for a reference manager. If I can’t use iPad EndNote, then why use EndNote at all? EndNote team, can you please tell where the problem lies and fix it please as soon as possible? Otherwise I will emigrate from EndNote.