Hi Elijah,
I'm Sumit, here to answer your query at the Microsoft Community.
Typically it is in WindowsApps folder in C:/ Program files, which can't be accessed normally.
Let us be sure of that.
Run the Treesize as admin and let me know if you are able to track it.
Treesize should tell you which files and folders are taking up the space.
https://apps.microsoft.com/store/detail/treesiz...
You can send us a screenshot after selecting the drive for the next steps.