Copy/Paste from documents (PDF, docx) - weird behaviour of diacritics When I copy text from PDF (Preview) or Docx (Pages) with Czech characters, some of the Czech characters get copied with their accent "stuck" to them. 

To make this even weirder, this behaviour is pretty inconsistent: Sometimes "ř" is copied well, sometimes it isn't. Also, it doesn't seem to be connected to specific font. But I think this happens more often with fonts, that are not native for OSX (such as Cambria, which happens to be MS Office default).



Result of CMD+C for "í": "í́"

Why is this happening?

Edit


OSX: 10.13.6 (although it happened to me on older OS and even other machines)
apps, I've copied the text from: Preview (PDF), Pages (doc, docx)
apps, where I've pasted the text to: anything (from Sublime text to text editor in StackExchange, see above)


Also, I've noticed that this happens often at the ends of words (possibly ends of lines). I will confirm this once it happens again, as the behaviour is frustratingly hard to reproduce.
Regarding copy/paste from pdf, treatment of non-ascii characters can be botched by the particular pdf creation process.  Without info on how your pdf files were generated, such as the encoding and the fonts used, it's hard to determine why the results are not correct.