Duplicate photo names being overwritten

[heathenibis]

Hi, thanks so much for putting this together.
While validating all my pictures downloaded, I saw that there were pictures missing randomly. When I looked into it further, it's because there were multiple files with the same filenames, and therefore the system overwrote those files. Where I should have two files named IMG_004 (with one of them being IMG_004(1)), I only have one.
I cannot sort photos by filenames on Google Photos to see what all has a duplicate name. Any suggestions?