Why Certain Untracked Folders Are Not Stashed with git stash -u?

Good day everyone, please I used git stash -u to stash changes. While some untracked files were stashed, my supervye folder remains untracked. Interestingly, other files copied from the same location were stashed successfully. My .gitignore doesn't explicitly ignore this folder.
Is this behavior expected for untracked folders with git stash -u? Or could there be another reason the folder isn't being stashed? @Middleware & OS