When I upload an image in firebase storage it keeps the image but when I upload an apk file its automatically disappears. What is the problem

I can’t download files located in a folder in Firebase storage after they reach a certain size, is there any solution to this problem?

I am confused whether firebase storage is safe as I was building notes app for my institution and I secured my storage to allow only read for authenticated users. Despite doing this I noticed that there was a link when I opened that link on incognito so I was able to view my file how??? Incognito, I was not signed in…

I have Firebase Storage that holds hundreds of files secured by Storage rules. The rules check if user requesting the file (URL) has sufficent permissions in Firestore Database.