Files disappeared from phone after update (OnePlus 2)

[AC Question]

After an update, about 500mb of files disappeared from my downloads folder. All files except for around 10 had disappeared (dont think it has anything to do with their file format as other files of the same format disappeared as well). However files within subfolders inside the downloads folder were fine. My android shows that the space is free (51.7 gb used of 53.9) and i cant find the files with diskdigger when i tried even though it had found files i had deleted from a year ago. However when I plugin my phone to my PC, my pc shows that 52.2gb of space is being used (although i still cant see/find the files on pc except for 1 126b M3U file). Im wondering if theres anyway to get the data back and what is causing the issue. Thanks