I recently migrated a Classic Quiz to a New Quiz in my sandbox course to do some testing. In the Classic Quiz, there is a brief set of up-front instructions for students which includes two links to PDF files (both of which have been uploaded to my "Files" area of the course). When I click on the link to test out the links, they download as expected with the proper file names. After I migrated this Classic Quiz to a New Quiz, the instructions migrated, but the file names of my two PDF files completely changed...
*As a side note, neither of these re-named files are in my course "Files" screen. It seems the files get saved to a different location, and I have no way to access them. 😟
I downloaded both of these PDFs to ensure the content was still intact for both files (thankfully it was). However, I am unclear why the file names have to change. If a student had to download multiple files prior to taking a quiz, I could definitely see how this could be confusing to know which file to open... especially, if the directions told students to "Download the LP1 Lab.pdf file", for example...and then they get a file download similar to what I've shown above.
4/18/2022 Update: I chatted with Greydon B from Canvas Support about this. My case number is 08707518 for anyone that is interested and wants to reference it for their own use.