Firebase realtime database photo URL issue

Hi, I got some issues with my app. It uses Firebase as the realtime database. It happens by RANDOM. A user sometimes cannot upload their profile photo. The photo’s URL is shown as below in Firebase.

photo: “file:///var/mobile/Containers/Data/Application/1EAC1036-2551-42B2-9EE4-9F3D88127359/tmp/DB4F1C0B-1FD2-43B4-8C99-02AC32A6639B.jpg”

I have no idea about this. Could it be the blocks’ problems? But most of the users have no problem with that. Their profile photos are stored in the cloud that we can open them directly with the URL.
Hope someone can help with this. Really appreciate it!