PDF cant drag and drop and cant manually upload and reference (Sync)

What I’m trying to do

I want to add a pdf into my vault for the first time since getting sync. If I manually copy it into the file browser (windows) it just dissapears so I can’t put it in the location I want and then reference it. If I drag and drop it creates an Untitled folder and opens that and when I go back to the page that I want to embed the pdf it just says “file name” could not be found.

Things I have tried

Nothing else yet.

Check if Settings → Files and links → Show all file types checkbox is checked. This is the most likely reason of missing file. Otherwise use [link text](file://disk_letter:/full/path/to/your/pdf) notation.