Editting problem(Uneditable)

I heard inquiries about this problem several times, but the document was not locked.

I will attach a pdf that is currently being edited and a pdf that cannot be edited, so please take a look.
Why are some things being edited and some not?
How can I make the non-editable pdf editable?

It is causing me great inconvenience. Please help me.

  1. uneditable
    경제전망. 공급측면에서 확인되는 부담 요인.pdf (940.7 KB)
  2. editable
    유안타 데일리 산업별 이슈 및 코멘트 (21.02.23).pdf (615.5 KB)

In one case the PDFkit of macOS might corrupt the text layer of the document after editing, that’s why it’s automatically flagged as not editable.

Is also it a problem related to language?

So pdfkit is Apple’s problem, right? crying

Yes, especially Eastern languages cause this.

Unfortunately it is.