Why does my iPhone not index Folders correctly when iPhone connected to internet

When my iPhone has Wi-Fi enabled, my Folders held on my iPhone's internal memory (Files app.) does not index properly (complete folders are not able to be located using the Search function in the Files app.).

I know it is a Wi-Fi conflict because as soon as I disable Wi-Fi and use the File app. Search function, all Folders are indexable (searchable).

I do not have iCloud Backup turned on, so why is there an indexing conflict associated with the status of my Wi-Fi?