A Microsoft file hosting and synchronization service.
I contacted OneDrive support.
Thanks for contacting OneDrive support. I would like to inform you that, there is an ongoing issue with the search option and our engineering team is aware of it and they are working on it to find a permanent fix. As of now there is no ETA on having this issue fixed. However, there is two workarounds:
Work Around 1: Manually look through the various folders on web. [very manual]
Work Around 2: Install OneDrive in your PC, and search via File Explorer. You can install the OneDrive in your PC through this link: https://go.microsoft.com/fwlink/p/?LinkId=248256
Please have patience with us and as soon as the fix of this issue comes. I will update you regarding this.