Preset Import Issue

I've read many posts with similar issues, but none of them seem to be suffering from quite the same issue as I'm having.

A little backstory:

I'm using primarily Adobe Lightroom (not LR classic!) on PC. Recently I purchased a bundle featuring many different preset packs from One Presets (https://1lightroompresets.com/pages/collections-1). I was able to quickly and successfully import most of these packs but there are a few stragglers that just won't import and I can't understand why, for the life of me.

Whenever I select the .zip folder containing several .xmp files (which has worked many times before this), it says the presets were successfully imported (as usual). The only difference is that some of these folders just don't show up in Lightroom, even after the application says the import was successful. I am seriously mind-boggled. As I said, most of them work perfectly fine, but the same few just refuse to work.

I have tried:

• Importing individual .xmp files one at a time instead of the .zip file.
• Resetting hidden presets.
• Browsing through the manage presets option.
• analyzing the differences between the presets that work, and those that don't (no visible difference).
• Looking for the installed presets in the Lightroom program folder.
• Installing the presets to my LR mobile via a flashdrive.

This issue has been frustrating me for too long. If anyone has encountered this issue on PC, or knows of any alternate ways to install presets, I would love to hear from you. Any and all help is welcome.