Videos no longer syncing from computer to iPhone photo library

When syncing photos from my computer to my iPhone I copy photos from a main folder with several sub folders, including several with videos shot using the iPhone and other devices. Last time I synced my phone I noticed that none of the videos synced across, and in fact the ones already present were deleted from the phone.

In iTunes, under 'Photos' in the phone menu all of the desired folders are selected, but the video folders show 0 files, even though I can navigate to those folders and see all the same video files present. After syncing the phone, the video-only folders are not present on the device, and the other folders contain only photos, no videos.

This is new behavior, until yesterday all the videos synced across without issue. The problem appears to originate in iTunes rather than on the phone, since iTunes does not appear to be seeing the video files. I am using an iPhone 5s with iTunes version 12.5.5.5 on Windows 10. I have tried all the usual restarts, checking for updates, etc. Any suggestions would be appreciated.